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View Full Version : Li-Ion/Polymer 3.6v batteries... your experiences?



Novastar
04-17-2007, 01:53 PM
I haven't seen much discussion regarding these, and as some of you already know--I'm a big fan of them.

I would love to see others experiences with them, thoughts regarding the technology--and where it might be going and so forth.

Here is what I've found so far. I will use a 3.6/3.7v Li-Ion 2400Mah 18650 cell as the sort of "basis" (so no one is confused as to what batteries I'm talking about):

POSITIVE EXPERIENCES:
* Effective 4.2v "starting" voltage
* Lightest in weight (it's lithium!)
* Safe for environment (Alkaline is awful for it)
* No memory effect (unlike Ni-Cad / Ni-Mh)
* Low discharge when unused
* Li-Ion tends to maintain its voltage over a discharge cycle
* Lasts just as long (or longer!) as any other cell for its size AND voltage (good or better energy density)
* 3.6v per cell is far better than even a smaller 1.5v cell in my opinion--especially for LEDs
* One cell can light up nearly any Luxeon LED... or most any other LED for that matter (despite it not necessarily being at the "maximum" brightness, depending on the LED type, color, etc.)
* Better variance in battery setups--less cells can achieve more power with less space used
* PCB protects for: over-drain, over-charge, over-discharge, short circuits, over-current draw, etc. -- it protects your cells AND your driver! In other words--if you make a wrong move... the PCB will generally save you.

QUASI-"NEGATIVE" EXPERIENCES:

* They are fairly expensive, even for one cell. Then again, I can't IMAGINE how many 1.5v alkalines you'd have to buy in order to equate the TOTAL lifespan of a 3.6v Li-Ion cell. No clue.
* The small PCB that must be on the battery to control/regulate the cells will drain a tiny bit of current (something like 1mA or negligible amount)
* When the PCB is tripped (for whatever reason), the voltage will read 0v, and the battery must be plugged into a charger to "reset" the circuit.
* Long charging times--well.. maybe not, but I suppose 4 hours to charge the battery is more of a "neutral" experience?
* Voltage increments are (obviously) very large... you can't exactly get "5v" without a regulator. You have 3.6, 7.2, 10.8, 14.4, etc. Then again, the voltage is not always the most important thing for LEDs... it is the amperage/current that is key.

Ok... that's it for now. Anyone else who has Li-Ion experience (and no I don't mean Lithium 3v primary cells)... chime in!

The last thing I can say is... these will come into play BIG TIME for anyone wanting a Tri-Lux kind of setup. 3.6v x 3... or 3.6v x 4. Trying to do that with 1.2v rechargeables or even 1.5... would be a nightmare in my opinion.

987654321a
04-17-2007, 08:59 PM
li-poly, no way in hell will i buy that. watch this video why.

http://www.youtube.com/watch?v=SQ0SNESIkWk


ni-mh, is the best you dont have to discharge when you want to recharge it ni-cd leaves a memory

Novastar
04-17-2007, 09:12 PM
Ridiculous argument.

Overcharging almost any battery will result in a catastrophic fire or explosion. If you're saying Ni-Mh or whatever other battery... can't achieve that kind of explosion with INTENDED ABUSE... you're in for a big surprise.

987654321a
04-20-2007, 05:31 PM
oh i know alot about rechargable batteries i use them in my airsoft guns. yes of course every battery is going to turn into a fire ball when overcharged, but i would go with ni-mh or ni-cd, because they dont turn into a fire ball when they are gently tapped. i had a bad experience with a li- poly in my airsoft gun. i was playing at a canyon and idk how but my gun slipped outa my hands and hit the stock, that instant i stepped away knowing that the li-poly in there is going to explode. ended up going home with a $300 gun with a giant hole it in. li-polys are amazing but even when hit with a stick lightly, or bent or mishaped somehow they will explode and you wont like it. all the money you had spent on that nice saber would go in the trash. i mean think of it when dueling with that li-poly powered saber you have to be gentle with it and be careful not to hit the other saber too hard or your li-poly will explode. so it would suck for you alot. ni-mh, or ni-cd. all the way bro.

Novastar
04-23-2007, 01:08 AM
Sorry to hear about your experience with the Li-Poly pack. My guess would be that + must have crossed to - when you dropped your gun. I wasn't there, so I don't know... but THAT would cause the pack to blow--as you probably well know.

However, I've now dueled with or "put into action" Li-Ion-powered sabers extensively (as in they are used and recharged several times a week), and not a single one has exploded. Not even after needing re-wiring, repair, etc.

I don't have any experience with Li-Poly, but my guess is you had some inferior packs, the PCB failed, or they just became too hot.

That being said--batteries should be housed in something stable that doesn't allow them to come into contact with objects, and also to protect them from overheating. No battery of mine in any saber (alkaline or otherwise) is able to be "hit" directly. Same to be said about allowing heat to get to them--they are heavily protected.

It would be silly to think slamming tiny cell batteries on a rock or (let's say) using a hammer against them would yield anything but dire consequences.

The battery cell type will not matter when and if the batteries are abused.

neophyl
04-30-2007, 12:39 AM
Did the lithium in your airsoft gun have the protection circuitry ?

987654321a
04-30-2007, 03:05 PM
yep. many airsofters i know have bought brand new li-polys from different hobby stores and got a stick and tapped them, and they still blew up, li-ion doesnt blow up but when overheated can cause a fire :?

Novastar
04-30-2007, 09:24 PM
987... different packs allow for a certain "draw"... although I don't think that's your problem--I'm sure the batteries are not being "treated" properly by the airsoft guns.

Again, to confirm--EVERY single Li-Ion pack I have ever bought (and I use them alot--bought at least 20 packs)... have never once caused any problems.

Just recently, I short-circuited a pack by a stupid mistake... thought I killed the pack... the PCB tripped, and 24 hours later--they were fine.

987654321a
04-30-2007, 10:11 PM
well im saying like faulty li-ion batteries but the ones your getting work fine, li-poly has alot of juice and it can power something for a long time and with more power.

Novastar
04-30-2007, 10:43 PM
Right, the Li-Polymer tends to have about 10 to 15% more energy density ("punch").

I'm still unsure as to why your packs are blowing up.

At the risk of discrediting some site--where do you get them from?

neophyl
05-01-2007, 12:41 AM
Just reading this thread as at the moment Ive no experience with lithiums as (lots with nicd and nimh though) but one thing I notice is that Novastar is always reffering to Lith-ION and the problem packs reffered to by countdown are Lith-POLY.

Maybe thats why Nova hasnt had the same problems.

Nova any chance you could list some of the places where you have bought batteries and chargers. While I might not be ble to pick stuff up from them (due to being in the UK) it would at least let me see exactly what has been used successfully and try and source a local supplier. Its one battery type I wouldnt mind having a play with.

Novastar
05-03-2007, 04:55 AM
No problem Phil... I'd be glad to help--especially when so many have helped ME out too.

I like Li-Ions for several reasons, but mostly because they work so well for our given application (as stated in the beginning of the post).

Just because people haven't used them much--doesn't mean they aren't statistically excellent.

You can find these types of batteries right here at TCSS now! :) Other sites that focus on solely batteries allow you to go for ones without the PCB, without the pre-soldered/spot welded "tabs"... or buy them in bulk.

I'm sure as the months progress--new styles will be coming out. I've no doubt that they will soon become mainstream for our causes... here's a good reason why:

Many people have asked "can I run a Lux V with a 9v battery"? The answer is yes--you can. But not for very long.

You can run a Lux V *perfectly* on a 7.2/7.4v pack. Direct-drive that is.

Erv's board regulates current, so a 7.4 2400 mah with a K2 @ 1.3A draw... runs like 3 hours and 45+ minutes!!! No joke, I tested it.... but had to cut the test short since it was getting RIDICULOUS continuing to leave it on for long periods.

erictank
05-14-2007, 08:45 PM
No problem Phil... I'd be glad to help--especially when so many have helped ME out too.

I like Li-Ions for several reasons, but mostly because they work so well for our given application (as stated in the beginning of the post).

Just because people haven't used them much--doesn't mean they aren't statistically excellent.

You can find these types of batteries at batteryspace.com or allbatteries.com (I think that's it). You can go for ones without the PCB, without the pre-soldered/spot welded "tabs"... or buy them in bulk.

...

Erv's board regulates current, so a 7.4 2400 mah with a K2 @ 1.3A draw[/i]... runs like 3 hours and 45+ minutes!!! No joke, I tested it.... but had to cut the test short since it was getting RIDICULOUS continuing to leave it on for long periods.

Do you get the cells with the integrated protective PCB, or do you build your own? I'll be starting my first saber in the near future, and was thinking about using the 18650's - if I do a K2 setup, I'll need two, hooked end-to-end, to generate the 7.2V, and the prefabbed (multi-cell) packs all seem to come configured side-by-side.

Also, how do you hook them up inside the saber hilt? The ones with the internal PCB don't seem to come with the tabs, and the ones with the tabs don't come with PCBs - how do you make the connections?

Maybe we ought to get you to write a Li-Ion battery tutorial for us :D .

-Eric

Novastar
05-16-2007, 03:28 AM
Hi Eric... welcome to TCSS!

Let's see...

1. Integrated PCB, yes--in the sense that I don't wire them up myself, but it really is not hard to do... you are simply allowing the PCB to "inspect" the batteries BEFORE the batteries provide anything to any board/driver/etc.

One way to "learn" how to wire your own is to buy one pack of 7.2/7.4... and a 3.6v... and then look at the PCBs. Snap photos. Write squiggly stuff about 'em. 'Nuff said. :)

2. 7.2v/7.4v end-to-end... this is possible to buy indeed. You need only look online a bit more.

In fact, we are using *EXACTLY* this for the blasters of BOP II. Coming in only a few weeks!

3. Tabs / wires, etc. ... this again depends on the company you get them from. It does indeed SUCK if you don't get the tabs, as trying to solder directly to the battery is both dangerous... and sometimes not very possible. BE CAREFUL.

I have no experience with the non-tab versions, and although I have been told of a possible solution--I will *NOT* recommend it, since it could become dangerous if someone misinterpreted it.

4. An idea for you... if you buy two separate 3.6v batteries with tabs... then buy a 7.2/7.4 PCB... you can easily wire it up yourself... and "lay them out" any way you choose.

I would recommend NOT going with the end-to-end setup... it uses too much space. But side-by-side WILL fit in a 1.5" ID tube (sink tube or otherwise). Plus, you can use space above and below them!

Corbin was able to fit a TRIAD of 18650s for his new Penny Killer saber... but it had a very custom tube for it to sit inside.

Good luck... and happy Li-Ion... ing. :?:

Novastar
05-25-2007, 01:55 AM
As a matter of note, I wired up a second v1.2 Plecter board driven saber (this time a Lux III red/o with my "sith sounds", lol).

I haven't confirmed the run-time being like the other Green K2 that I setup, but I imagine that a single usage cycle life should be similar since the current is again... 1.3A. About 3.5 hours of use the way I had it set up (flicker + Erv's driving + pwr management, etc.)

The Li-Ions are dandy fine, and 7.4v gives them just what they need.

Also, Corbin mentioned having problems running 3 x 18650s on the Killer Penny saber. Ace said it was giving too much voltage than they expected (which is not surprising).

3.6/3.7v x 3... is NORMALLY = 10.8v/11.1v
...well... that's not quite how it works with Li-Ions.

Again, since they tend to maintain voltage over a given "run" of your battery's charge life... you will not see a drop in voltage until deep into the cycle... and then a large drop-off at the end, where the PCB will "kick in" prior to you killing the Li-Ion completely. So...

3.7v x 3... is ACTUALLY = @12v

Don't be fooled. Meter your Li-Ion batteries. You will find that they generally meter at about 4v, and maintain that (for the mostpart) throughout their charge cycle.

I love these things because they are PERFECT for most Luxeon LEDs which have a fwd v of 2.95 or 3.6 or 3.4 or 3.85, etc. etc.

Strydur
05-25-2007, 10:28 AM
Coming soon!!!

More powerfull AA Nimh packs
AAA Nimh packs
Li-ions
Li-ion packs
Li-ion smart chargers

xwingband
05-25-2007, 10:50 AM
Yum! Especially the li-ions. :D

Novastar
05-26-2007, 12:25 AM
Yup. Agreed! Thanks Tim!

By the way, BOP II debut was SIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIICCCCCCCCCCCCCCCC CCCCCCCCCCCCKKKKKKKKKKKKKKKK!!!

Everyone loved it... absolutely LOVED it. My acro was freakin' clean and perfectly timed... got applause right then and there... sweet!

Some mistakes occurred (as is to be expected with a live show by volunteers)... but it was great!

Can't wait to post footage, but I'll wait until after tomorrow night's performance where it will be more "pimped" out... heheh

jsippy
06-07-2007, 11:09 PM
Greetings all,

I feel I must post this here, because I do not want to see anyone get hurt...

I too play airsoft, and I have done some pretty exhaustive research into Li-Po (aka Li-Poly) batteries, and can assure you that they are currently UNSAFE for use in a lightsaber (or airsoft gun for that matter).

Li-Ion and Li-Po batteries are similar in their chemical makeup (Li-Po is short for "Lithuim-Ion Polymer") and all Lithium-Ion batteries are known to behave violently (ie. catch fire or explode) if charged or discharged incorrectly. Normally this is not a problem thanks to a small circuit contained in every Li-Ion battery that is designed to shut the battery down if there is a problem. However, the amount of time a Li-Po battery will tolerate a problem situation is extremely short. Many people in the RC Flying and Airsoft communities have inadvertantly discovered that the protection circuit in a Li-Po simply can't shut the battery down fast enough to avoid starting the chemical reaction that leads to a fire or explosion.

Reportedly, the Li-Po battery manufacturers are soon going to release the next (4th) generation Li-Po's which will contain circuits that react faster and have tighter tolerances than the previous versions. These new batteries will even feature stronger cases to help them deal with physical shock, and safely contain the chemical reaction so that they do not explode, but instead puff up and release gas build-up slowly. I've been checking in with my local hobby shop frequently as to the expected release of the 4th gen's (more for airsoft use than for lightsabers), but there's no definitive date set yet.

I think that in the near future, Li-Po's will be the battery of choice for hobbyists such as ourselves, but for right now, they are just way too delicate and have far too dangerous consequences for use in our hand-held lightsabers.

So please, don't get yourself or your loved ones burned, stay away from Li-Po's for now. Use Li-Ion's instead.

Cheers,
John

Novastar
06-08-2007, 01:12 AM
Hi John... this is an EXCELLENT finding... thanks for expressing that safety concern! We don't want anyone getting hurt.

However, I am also trying to reinforce the differences that many do not know about:

* Lithium PRIMARY
* Lithium Ion
* Lithium Polymer
* uh... Lithium. Alone. :)

Just joking on the last one, but... I am often surprised how people will say "I hear lithium is dangerous", and completely give up on it.

I understand your concerns with Li-Po, and after hearing countdown's story ('987654321' on here)... I can see that there is something to be said for people to have a DISTINCTION.

So for everyone reading... just make sure you educate yourself. When people say "lithium" batteries... they have no idea what they are saying... they need to be SPECIFIC.

Finally, I would be curious to understand what requirements, load, current draw and all of this is being "asked" of the Li-Po batteries under these airsoft guns and model airplanes.

I am sure they are quite different than turning on a simple LED (and/or speaker) for an extended period of time.

Jacen_Aurion
06-08-2007, 12:13 PM
I play airsoft a ton, and with my first gun (fortunately it was only 50 bucks and my new better gun would come in the next day) i didn't even drop it, but the NiMh battery inside was charged for 24 hours as opposed to 4 by a very good friend of mine (who is still a very good friend) and as a result the battery broke. I'm very fortunate to have not had the battery blow up in my hands. He is now much more careful with charging batteries. If you're going to use Li-Po batteries or NiMh batteries then i strongly suggest you set a timer for however long you need to charge them and then sit by them and do something while you have them charge. If you get a smart charger from any of the big airsoft places (i'm assuming you could use the same kind of battery for a lightsaber) then it will stop charging your batteries when the charge is full. Good luck with the rest of bop nova, and I have no doubt you of all people is extremely careful.

Novastar
06-09-2007, 05:48 PM
There will be NO charging Li-Ions without smart chargers...

That's why I bought like 6 of them.

Ganoran
06-15-2007, 01:15 AM
Okay, I'm a total newb to the pieces of batteries. What's PCB stand for and what does it do?

Novastar
06-15-2007, 01:48 AM
It just means printed circuit board.

In a nutshell, Li-Ions need to be "controlled" in order to prevent several issues that would be natural to the design materials:

* Overcharge ( >4.2V )
* Overdischarge ( < 2.5 V )
* Over drain ( > 3 Amp -- depending on the battery set )
* Short circuits

That is for a 3.6v battery.

So in other words--a Lithium Ion battery is "smart" in the sense that it takes care of itself as best as possible.

This does NOT mean that they are immune to having problems. Although... I've not run into any myself.

So far, it sounds like people HAVE had issues with Lithium POLYMER... which is a different technology vs. Lithium Ion (or Lithium Primary for that matter).

Ganoran
06-15-2007, 12:11 PM
Thanks for clearing that up.

Novastar
10-08-2007, 12:36 AM
Old topic but just wanted to say again--these Li-Ions are GREAT...

I've been trying a Luxeon III "light side" (blue, green, white, royal b, cyan, etc.) with *NO* resistor on the circuit--just to find out what would be going on.

NOTE: I DO NOT RECOMMEND THIS TO ANYONE, I am trying it as an experiment, considering the fwd voltage of the LED being pretty close to the Li-Ion's voltage, and the fact that I've considered the possibility of the LED getting "killed" by drawing too much. It's worth $8 to $12 for the experiment (or whatever a Lux III costs, I forget).

So far... no problems other than the hilt getting pretty darn hot over some time!! :)

xwingband
10-08-2007, 05:14 AM
That setup should be fine Nova... flashlight people do it all the time. It's what Ultra was doing in his stunts, etc...

Not the best but it works.

Onli-Won Kanomi
10-13-2007, 02:18 AM
These 3.6V Lithium Ion batteries sound great...I really hope they are coming to the store soon and though I do see a Li-Ion charger available in the store I only see NIMHs listed in the rechargeable packs, which are out of stock anyways so I had to order a battery holder for alkalines instead...oh well it seems theres always another great product coming to look forward to ordering here :)

One hopefully not TOO dumb question I do have is about using those battery holders with these new Li-Ion batteries whenever they become available here: most battery holders I've seen in sizes like AA or AAA have marked on them that they are rated for 1.5v batteries [presumably normal alkalines?] ...will they be safe to use higher voltage Li-ions in and deliver their full power or will we need new higher-rated battery holders to put them in too??

xwingband
10-13-2007, 05:29 AM
That's a great question... I think for rechargeables the best answer is to solder together your own pack and heatshrink it up.

I did once use the raw batteries in a a regular holder... the spring tension caused them to leak over time. Also they weren't button tops which was also a pain too, but that more related to the specific ones I bought.

Really with rechargeables the ideal is to have a port or quick disconnect so the idea of a holder is to be able to pull them out individually? That's very counter-productive and unless your charger works that way it's rather pointless as all I see are detractions.

Eandori
10-14-2007, 09:03 PM
There is no clearcut answer, because it depends on a lot of factors. But here's some facts on the different cell types.

Lithium Polymer (Li-Po): Very high storage capacity, Very non-standard cell types, requires cell regulation circuitry, Highly dangerous if misused, best for low current applications. LiPo does not suffer the "memory effect."

Lithium Ion (LiIon): Very high storage capacity, Very non-standard cell types, requires cell regulation circuitry, less dangerous if misused then Li-Po, best for low current applications. LiIon does not suffer the "memory effect."

Nickel Metal Hydride (NiMH): Storage capacity varies greatly with cell quality as higher capacity NiMH can have up to 4x the capacity of another NiMH of the same size/shape. The highest capacity NiMH cells approach LiIon, while the lowest capacity NiMH cells are closer to NiCad. No cell regulation circuitry required. NiMH has very standard cell sizes. NiMH provides the highest available current supply of all the cell types i.e. extremly low internal resistance. NiMH are best for high capacity, high current applications or in places where cells are exposed to environmental abuse. NiMH does not suffer the "memory effect."

Nickel Cadmium (NiCad): NiCad is the lowest storage capacity of all the cell types, yet the 2nd best for providing large current supply with low internal resistance. NiCad's are the cheapest of the rechargable cells and require no regulation circuitry. NiCad's are best in low cost situations but unfortunately suffer from memory effect which requires an occasional full discharge.

=================================

-If your usage requires huge capacity, not much current draw, cell regulation circuitry is ok, and low cell abuse, then go with LiIon. That's the exact situation of a cell phone or laptop.

-If your usage requires a low cost solution, use NiCad.

-If your usage requires large capacity, and large current draw, use NiMH. This is the exact case for RC Cars where I can tell you from experience that some 7.2v packs provide upwards of 120 Amps of current in bursts and average out between 15-40 Amps of continuous draw. That's an order of magnitude higher then what a lightsaber will draw.

-If your usage requires large capacity, but inexperienced users will be building custom hardware, and the cell will be put through abuse, I would reccomend NiCad or NiMH. Putting your cells inside a sometimes novice made metal tube, with novice solder jobs, and smashing it into other devices with high impact, I would say stick with NiMH and NiCad. Sure, cell phones use LiIon, but they are built by professionals and don't smash into each other.

Having said that...

If you are very experienced with construction, and patient enough to do things right... go ahead and use LiIon in your lightsaber and take the proper precautions using them. That means...
- Use the right chargers
- Make sure the cells are insulated from sharp edges to avoid damage
- Make sure your on board regulation circuit can survive a few hard whacks.
- Make sure your on board regulation circuit cuts off from cell voltage AND temperature. Or at least install a quick remove features to get those cells out of your saber and into a bucket of SALT WATER if a runaway condition occurs.

I'm personally using 8xAA at 9.6v (base rating) with 2500mAh of capacity for my saber. I will switch to LiIon at some point, just have not yet. Since the capacity is high, it's great for me. Since I use a Luxeon V I need the large supply voltage to keep my LED running at 1 amp.

Just a quick note on what mAh (Milliamp/hour) means, since I see people constantly butchering that. It means how many milliamps your cell will provide for 1 hour of time. So a 4000mAh cell will provide 4 amps (4000 milliamps) for 1 hour. If you pull 500mA out of that same cell, expect it to last around 8 hours. mAh is a rating of cell energy capacity. Period. The voltage of a cell, and how much current it can provide with extreme load are two different things independant of the cell capacity.

Hope that helps guys, keep up the good work!!

MATRIXtjb
11-30-2007, 03:41 AM
I just wanted to say i have 3 of them 3.7 LI-Ion batts and with the size of them they would work perfect for a lux v system with an ultrasound 7.4v would work wonders i was thinking it would prolly reduce the tube diameter abit

Novastar
11-30-2007, 06:28 PM
They certainly help with space issues, considering the extra voltage vs. size trade-offs.

Also, you can wire up a "triad" of 11.1v for Ultra's driver as well. It can handle up to 12v, and will simply "use" the extra voltage as current when needed with whatever setup you have.

On a Lux V, you should get a longer run-time at an ideal brightness when using 11.1v. Whereas with 7.2 or 7.4... you may only have ideal brightness for a short period of time.

Clockwork
01-03-2008, 09:10 PM
Hey Everyone,

this is my first post, I have been considering building a saber for quite some time and recently my girlfriend told me she didn't like me having a dark side saber (ANH-Vader MR) and wanted me to build a light side saber. Well who wouldn't jump at the approval of one's better half eh? So here I am. I have decided to go all out an get a CF when Erv gets the next batch done and I intent to use Li-ion batteries. Hence why this post is in this topic. My question is, using a either a Green K2 or a Green Rebel and the CF, should I plan on a 3.7/3.6v setup, or a 7.2/7.4v setup?

Jonitus
01-03-2008, 09:34 PM
Based on my own experiences, go with the 7.2/7.4 setup. With a pack of that voltage, and if you can get one with a 2400mAh capacity, you could get nearly 4 hour runtimes out of your K2 saber between recharge times.

If that kind of pack is not available to you, Li-Ion batteries are still a better technology, IMHO. Regardless, go with the 7.2/7.4 setup, so you can have a nice long runtime out of your saber.

Clockwork
01-03-2008, 10:25 PM
Based on my own experiences, go with the 7.2/7.4 setup. With a pack of that voltage, and if you can get one with a 2400mAh capacity, you could get nearly 4 hour runtimes out of your K2 saber between recharge times.

If that kind of pack is not available to you, Li-Ion batteries are still a better technology, IMHO. Regardless, go with the 7.2/7.4 setup, so you can have a nice long runtime out of your saber.

Thanks Jonitus, I had a feeling the 7.2/7.4v was more suitable. Is it worth putting four 18650's in the hilt to grab 4800mAh? or is that excessive?

Hasid Lafre
01-04-2008, 06:18 AM
if you got the space for it I say go for it.

Novastar
01-04-2008, 06:18 PM
I'd say it's excessive and expensive unless you need 5 hours of un-interrupted runtime (when going direct drive/resistor only).

I can only imagine how long a Plecter setup would run off of 4800mah. I'd imagine I'd see about 7 hours, considering I already saw 3+ off of an old runtime test with the v1.2 boards!

Stinky Bantha
01-04-2008, 06:36 PM
Speaking of runtimes, Novastar. Have you had any experience with a 4AAA cell nimh setup and CF driving a green K2 at say 1.3A? I need to cut down on size, and I was wondering if the runtimes were so abysmal with the AAA pack that it would be worth it to try to embark on a time-consuming quest to squeeze the 4 cell AA pack into my hilt.

Novastar
01-04-2008, 06:45 PM
Let's see...

* I've never used Ni-Mh nor Ni-Cad to power sabers--I think they are pointless for them, personally...
* What is the mah rating of the cells you're using?
* How will you be wiring them up? As in--will the voltage be 4.8v or 3.6v or what?
* If you go with this AAA thing... I'd wire them for 4.8v or higher.
* If you're looking to save space... do you have any qualms about Li-Ion? They will do exactly that: save space. :)

Stinky Bantha
01-04-2008, 07:04 PM
It's going to be 4 cells, so 4.8v. It's the pack sold here, and it's got 1000 mah. I realize it's going to be less than an hour, but I'm just not sure how much time the board will add since it's not really running at the full amperage all the time.

I'm definitely thinking about Li-Ion's, but for now I'd like to use what I've got. Moreover, I don't really need exceptionally long runtimes, since I can't think of a time when I would need to keep the saber on for more than an hour.

Novastar
01-04-2008, 07:10 PM
That should be fine then, as 4.8v will be able to maintain 3v or ~3.6v for a red or blue (respectively) Luxeon III or K2 quite easily. Erv's board will utilize any "extra" voltage and save it to maintain current (in a nutshell).

Also... no--don't worry--you WILL get an hour or more of usage time provided the following:

* you are using CF as you say
* you vary the current flicker a bit in the config file (i.e. don't set to a "static" blade)

With CF managing things and by adding in the blade flicker--you're essentially doing more with less. You should easily get 1 hour or more. I'd guess 1.5 hours of usage.

With the Phoenix Pyre sound font (which has MASSIVE flickering), it should last even longer! ;)

Stinky Bantha
01-04-2008, 07:24 PM
That should be fine then, as 4.8v will be able to maintain 3v or ~3.6v for a red or blue (respectively) Luxeon III or K2 quite easily. Erv's board will utilize any "extra" voltage and save it to maintain current (in a nutshell).

Also... no--don't worry--you WILL get an hour or more of usage time provided the following:

* you are using CF as you say
* you vary the current flicker a bit in the config file (i.e. don't set to a "static" blade)

With CF managing things and by adding in the blade flicker--you're essentially doing more with less. You should easily get 1 hour or more. I'd guess 1.5 hours of usage.

With the Phoenix Pyre sound font (which has MASSIVE flickering), it should last even longer! ;)

Thanks! I've been using the Episode IV font the most lately, but I think I'll set the flickerdepth a little higher. I like a more "alive" blade anyway. BTW I LOVE all of the sound fonts, don't stop making them!

Novastar
01-04-2008, 07:41 PM
I'll do my best with the sound fonts! There are a few more on the way...

Novastar
01-21-2008, 06:52 AM
Ah, speaking of Li-Ion batteries, I *FINALLY* saw a Li-Ion pack fry, which really wasn't much of my fault for the following reasons:

* The pack was an 11.1v pack which I did NOT buy myself... it came with one of the Hyperdyne sabers that was given to me

* The 11.1v was a non-18650 pack, probably 14500s, which are not designed as well as the 18650 series. I know this from someone who works DIRECTLY in the Li-Ion industry and also is affiliated with Apple.

* The pack fell out of the saber, hit hard tile... and destroyed the exposed PCB!

* The pack smoked, sizzled... and burnt a hole in the tile!

Now, in all honesty, it is POSSIBLE that the + and - leads crossed when the pack fell onto the floor, but... that would have had to be one INSANE stroke of bad luck due to the way the leads were. If so, I'd say the chances that I could repeat the same event with a pack wired exactly the same... would be 100 to 1.

I still have NO idea what *exactly* happened, as I've now worked with over 20 different packs of Li-Ion batteries. One thing is for certain, you certainly don't want to drop an exposed pack, and you DEFINITELY want to protect the PCB with padding if possible!

All this being said--I still say they are very safe. I didn't intend to drop the pack, and it surprised me to see that the PCB was not better protected. I always pad and protect the PCB on packs that I wire up myself.

DarthFender
01-21-2008, 07:23 AM
I have heard about interal arcing in battery packs where the contact between the cells is not great. It causes the contact points to get really hot. And could cause the pack to explode. But that would be true for any battery pack. Even Alkaline. Might have something to do with it.

Malaki Skywalker
01-21-2008, 09:52 AM
Ah, speaking of Li-Ion batteries, I *FINALLY* saw a Li-Ion pack fry, which really wasn't much of my fault for the following reasons:

* The pack was an 11.1v pack which I did NOT buy myself... it came with one of the Hyperdyne sabers that was given to me

* The 11.1v was a non-18650 pack, probably 14500s, which are not designed as well as the 18650 series. I know this from someone who works DIRECTLY in the Li-Ion industry and also is affiliated with Apple.

* The pack fell out of the saber, hit hard tile... and destroyed the exposed PCB!

* The pack smoked, sizzled... and burnt a hole in the tile!

Now, in all honesty, it is POSSIBLE that the + and - leads crossed when the pack fell onto the floor, but... that would have had to be one INSANE stroke of bad luck due to the way the leads were. If so, I'd say the chances that I could repeat the same event with a pack wired exactly the same... would be 100 to 1.

I still have NO idea what *exactly* happened, as I've now worked with over 20 different packs of Li-Ion batteries. One thing is for certain, you certainly don't want to drop an exposed pack, and you DEFINITELY want to protect the PCB with padding if possible!

All this being said--I still say they are very safe. I didn't intend to drop the pack, and it surprised me to see that the PCB was not better protected. I always pad and protect the PCB on packs that I wire up myself.

That must of been a shoddy pack! :shock:

Novastar
01-22-2008, 02:11 AM
Well, there is *probably* more to the pack than most might imagine in this case. I say "probably" because I'll have to make some assumptions that aren't worth getting all uber-nerd on to verify the data... but my assumptions are as follows:

NORMALLY, most Li-Ion packs have limits on the amount of "draw". That is to say, the PCB does not allow you to just say... "Hmm, ok, I wanna suck out 5 amps, so I gonna do it, here I goes...". Oh no. No, you cannot normally do this.

However, THIS particular pack was made for the Hyperdyne v2 saber. Now... I *MAY* be wrong, but it is very possible that it was wanted to draw more amps from the pack than one might normally take. Again, this is an assumption... so--who knows. But here's why I believe it could be possible (also based on some of what Eandori has mentioned):

* Pack became very hot to the touch (when it was still "alive & well") even during short usage times... i.e. 30 seconds to a minute. I can't think of any other pack that's ever gotten so hot and bothered to the touch!

* Shorter run times on higher settings. Well... that power is going SOMEwhere... and if you aren't getting around the "mah" rating run-time of the cells... it means we're drawing more than 1 amp.

* Due to the sheer amount of LEDs in the H2 saber... it isn't too far off to imagine that more than 1A wants to be delivered on higher settings. But hey, even a green K2 is "happiest" at 1.5A... :)

* I've never seen a Li-Ion pack burn until now. And I've "messed up" on a few before... but the PCB normally kicked in and halted anything bad.

Anyhow, this all COULD mean that the pack was altered to allow for higher draws. Again... I've no idea, but... it's possible.

Still, remember--it's also possible that the PCB cracked when the cells fell to the tile. Or maybe the leads crossed. Or maybe... it was just REALLY bad luck, a bad pack... or... I don't know. :)

Jedi Cloud
01-23-2008, 04:01 PM
I am fairly new to the forums and I was reading all about your topic on the lithium-ion packs. I am trying to have plans set up and drawn for my Graflex project and I wanted to use a LI-ion pack with 7.2v or 7.4v and at least 2400mA current. I am trying to incorporate the cyan lux 5 led into the hilt from TCSS. If there are no drivers available, what do you suggest as a best course of action to using/connecting the led to the pack until I am able to purchase the proper driver/board? Or should I use a different led all together? Oh I also found a site that has some 7.2/7.4 packs available. I have looked at a few but am unsure which ones will best suite my needs. Or if you have any suggestions, please feel free to point me in the right direction. :confused:

Thank you for your time.

xwingband
01-23-2008, 04:45 PM
A 2400mAh pack is big for a graflex... what driver are you thinking of? Other than a buckpuck I'd be hesitant at that size fitting.

Jedi Cloud
01-23-2008, 08:13 PM
I forgot to list the website. There is a website that has packs already made and there are some that I believe, could be small enough.

This website has a wide range of packs and a lot of different sizes. A couple of them are rc reciever batteries that I think could fit that they have. But then again I have been wrong before.

http://www.batteryspace.com/

For example one of the batteries from this link might work
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2439

xwingband
01-23-2008, 08:31 PM
Many of us are well aware of batteryspace... it's been a source for us builders for a while. ;)

That pack is too thick. 18650's like that don't fit in a graflex without the plastidip stuff... with that sucker barely fits in a 1.5" sinktube.

The only one on batteryspace that might fit is the stick one that they only sell in a five pack. You'd have to stack on top of it... might be difficult depending on the board.

Jedi Cloud
01-23-2008, 08:40 PM
Yeah thats a downer. Oh well, The 7.2 800mA pack from TCSS should work. But ten will that power the sound boards when they are available? Oh well back to the old drawing board.

Thanks for the help, very much appreciated.:p

Novastar
02-01-2008, 12:53 AM
7.2v are fine to feed to an Ultraboard or Erv's Crystal Focus board... however, an FX board is not meant to handle such a voltage load. At most, it is ok with 6v. 7v would be pushing it, and most Li-Ion 7.2v packs begin at 8.4v anyhow... so--chancing that would be bad.

The other option (frequently discussed on TCSS here) is using an FX board and a relay, or otherwise "splitting" the voltage to run such an FX board.

Novastar
07-09-2008, 04:06 AM
I'm still interested to see what folks have been doing (if anything) with Li-Ion cells.

As for me--I can't begin to imagine how much money I've saved with the recharger units + cells... and the space saved inside the hilt... and finally less wiring to deal with since one or two cells is all I've ever needed to use in order to power most sabers.

Granted... the "jump" from 3.6v to 7.2v *CAN* make it tough on projects for MR-style sabers, but... seeing as those are sort of low on the totem now... doesn't really matter.

strengthofrage
07-09-2008, 05:13 AM
My current project is the first I've used Li-ion. I am using the charger and 7.2 pack that Tim sells in the shop. I wanted something with a little more mAh (800mah on the li-ion pack from TCSS) but couldn't find anything that would fit inside the MHS hilts. I am excited about the size difference, it is going to make the internal layout so much easier.

Vardarac
07-09-2008, 05:38 AM
Can you discharge Li-ion cells in parallel for added capacity? I've heard that you can do this with Ni-mh, which is very nice considering that most of those carry at least 2.5Ah nowadays (6 cells/2 sets of 3 in parallel = 3.6V @ 5k mAh >:D)

BlackDOG
07-09-2008, 11:25 AM
I am using Li-Ions in both of my sabers......I have had no problems with the one I am currently using and would not make my newest work at all without the Li-ions (space issue).

As long as you follow the proper steps (PCB, Appropriate charger, dont abuse the cells) these are great.

bd

Novastar
07-09-2008, 03:45 PM
Can you discharge Li-ion cells in parallel for added capacity?You lost me a bit... but... if you mean to ask can you do the following:

18650 Cell of 3.6v Li-Ion @ 2400mah (as example)

2 x 18650 Cell wired for 7.2v @ 2400mah
2 x 18650 Cell wired for 3.6v @ 4800mah

...yes. :) AKA parallel & serial or whatever. You can even do an 11.1v setup... you know... whatever. :)

Granted, you pretty much need to buy the correct PCB for the specific setup you want with your cells. Or just buy a pre-wired pack. I usually do this, so that I don't have to screw around with my life/fire/incorrect wiring, ya know? It's worth a few extra bucks.

I mean sure, if it cost DOUBLE to get a pre-wired pack... I'd do it myself... but it doesn't. It only costs a few bucks. My life = worth a few bucks.

Although it ain't worth $30 extra. Just kidding, lol. :D

Oh.. and STR of RRRRRRrrrrr!! ... it's true that the cells Tim has in the store are fairly low capacity, but... it's about right for the cell size. The 18650s (do an online search) will get you at least 2200mah... but yup, they are bigger and fatter than a "normal" AA cell.

You can fit one in the MHS... but not alongside one another. You can only fit two as a "battery stick", hehehe.

This is another reason why I did not use a "full" MHS setup for my Flange III sabers. I used a mixture of the 1.25" blade holders, then 1.25" sink tubes... then the MHS coupler... THEN 1.5" sink tubes. That was key in fitting TWO Li-Ion 18650s "double-barrel shotgun" style (side by side).

Barely. :) They BARELY fit. :)

Kant Lavar
07-10-2008, 03:58 AM
Oh, goddammit. I just ordered one of those side-by-side 18650 packs for my cyan/Corbin saber.

...

I may just take 'em outside for a minute and cut into the heatshrink and see if I can mod them into a battery stick without killing myself.

strengthofrage
07-10-2008, 05:11 AM
Ah, that makes sense Nova :) I was looking at the battery website you linked me and the dimensions they gave for the side-by-side 18650 packs were just under 1.5" wide. I didn't want to mess with anything that wasn't already an 'assembled' pack my first time with Li-Ions, I figure since there is a recharge port it wont be a big deal. If the run times bug me I can always try a new pack.

Novastar
07-10-2008, 03:27 PM
Kant... if they have heatshrink on them and you're careful NOT to cut into the battery coating itself, you MIGHT be able to separate the cells, but... it's likely you'd have to unwire the PCB, remember how it was wired, and then re-wire it. It's nothing horrible, just don't get it wrong!

STR of Rrrr... the runtimes should not bug you at all if you got the 18650s. I mean, that's about the highest you can get for the cell size and all that. Li-Ions have the best energy density per square mm/in/whatever compared to "normal" alkalines or Ni-Mh or whatever.

As a matter of note, I ALWAYS wrap the cells in at least a few thin layers of electrical tape prior to placing them inside a 1.5" sink tube. Obviously, this will help rule out battery cells shorting to the tube itself. It also makes it tougher for the cells to get damaged... although they BAAAAAARREEEELY fit inside the 1.5" tube in the firstplace, so... you have to be a bit of a precisionist with 'em to make it work! :)

The batteries were the biggest nightmare for me on the Flange III sabers. To this day--it can be like pulling teeth since I'm unable to make a sort of "cradle/chassis" for the electronics: how could I? Besides, a bunch of stuff goes on TOP of the cells (the motor, indicator LEDs), so there's hardly any room anywhere!

Eandori
07-10-2008, 06:12 PM
Here's my take on batteries for sabers, and I'm fully prepared to debate all these opinions :)

Best Cell for a LUXEON based lightsaber:
- In terms of runtime and energy density versus cell size... Lithium Ion
- In terms of customizable ability for different sizes, stats.... NiMH
- If you need to draw large currents out of the cell for some reason (clash flash, etc.)... NiMH
- If you are going to use a very cheap charger or do it yourself with a power supply... NiMH

Best Cell for a Hyperdyne based lightsaber:
- Probably NiMH in all cases... unless you can find a Lithium Ion pack that easily can output a solid 4 amps until the pack is dead.

Stay away from Lithium Polymer batteries (Li Po). Because they explode with vigorous force and much energy if they are damaged. Damaging them entails overcharging, overdepleting, or something sharp puncturing the cell and shorting it out. Although they COULD BE used for a saber I'll NEVER reccomend it to somebody. Because if you were green enough to not REALLY UNDERSTAND your cells to begin with, then you have no business making custom electronic devices with LiPo cells.

In every case where NiCad (Nickel Cadmium) cells are used... NiMH is just better these days. Except... leakage current I suppose. NiMH have more leakage current then NiCad. But a quick charge and who cares about that?

Cheers.

gundamaniac
07-11-2008, 01:25 PM
Ah this thread is great. I'm thinking of beginning a saber project i've had in mind for about two years already in about two weeks (stopped by various things, like lack of funding for a CF, then when I had the funding, lack of CFs, then when I had the CF....well....school...and then when summer hit...summer school...and I'm out of that in two weeks. I hope nothing else stops my saber work....).

I've got limited space inside my hilt so I was considering Li-Ions. I've seen Novastar's sabers and I know his experience with Li-Ions...still, three things are potentially preventing me from using them. One was browsing this thread and me getting paranoid about mistreating the ells, despite knowing how many times Nova has used them (and the [mis]treatment of his sabers in stunt fighting, j/k novastar =P). The second was needing to buy a new charger for the cells, but that wasn't a big deal considering I'm essentially making a jump between two technology types. But the third one is the most prohibitive...I've sunk quite a bit into CF and can't really afford much now...buying the tubes and bladeholder for my saber project is already taxing my funds...and the recommended Li-ion pack (the 18650 i believe it was?) is about 40 bucks on batteryspace O_O. Oh man.

So I'm torn between Li-Ions and NiMHs. I'm working with essentially a 1.25" sinktube base so space is extremely tight and limited...I've been thinking of maybe picking up Tim's 800mAh Li-Ion packs because they seem small even if I don't get the phenomenal runtimes of the 2400mAh 18650 pack. Does anyone know about how much runtime I could expect out of that the 800mAh tcss pack with a green K2 and CF? Considering Nova uses a greenK2 and a CF with the 2400 pack and gets about 3 hours, I'm expecting about an hour from the TCSS pack, which, while not absolutely great, is still better than what I'm used to (somewhere between half an hour and an hour using 4 AAA NiMHs in an MR setup....ouch...).

Novastar
07-11-2008, 03:03 PM
All I will add is that Eandori is right (to a point) about the Amp draw from NiMh cells being better... but... here's what you can do with Li-Ions if need be:

18650 cells:

3.6v single cell setups = some can draw up to 3.5A or 4.2A (but I've actually seen one allow 8.5A draw, yes, 8.5A draw)

7.2v double cell setups = some can draw up to 5A (others limit to 4.2A... for some reason I don't see many allowing a higher draw)

11.1v triple cell setups =

32600 cells (big darn cells, essentially "C" or "D" cells):

3.7v -- you can draw something like 16A on a cell I've seen that is out there and available for purchase.

32650s -- same deal, 16A draw is ok.

I'm not 100% sure of everything out there, but... it seems clear that you can draw a decent amount of amps from Li-Ion if you really needed to do so. All depends on the cell type and if a polyswitch is limiting things, and what the PCB is also doing. Still... it can be dangerous (as with all cells), so be careful.

Malaki Skywalker
07-30-2008, 10:10 AM
I'm going Li-Ion... I want to use the 14500 pack from outta the store, anyone know what sort of run times I can get with a Lux III with one of those?

Cheers! :D

Novastar
07-30-2008, 12:22 PM
I haven't checked the suggested mah rating on the pack in the TCSS store, but... you simply use the mah rating to guage things--with ALL types of cells.

For example, let's say we have:
18650 cell, 3.6v rated for 2400mah.
If you draw 1A consistently, you should get.... @2.4 hours of usage.

blah cell, blah volts, rated for 1000mah.
If you draw 1A consistently, you should get.... @1 hour of usage.

This is consistent for ALL cells of ALL types, although the ratings will vary, and you won't always get *exactly* "one hour" or "two point four" hours or whatever.

Additionally, with things like PWM (Plecter board, Corbin, Ultra) and intense flicker & glow options (Plecter)... you will essentially extend the runtime because you are simply *NOT* drawing a consistent value over time... it's flickering on/off... pulsing a bit lower, then higher... varying the current... using excess voltage to be "changed" to current (so-to-speak).

However, when you figure extras like a speaker, a motor, indicator LEDs and that kind of thing... who knows--maybe it would even out.

The bottom line is... the only way to know more definitively for YOUR saber (and no one else's)... is to run it off of a full charge and "time it" to the best of your abilities. Even then, as the cells charge/discharge/charge/discharge... battery composition changes, and blah blah blah, heheh

Back in 2006/2007 I tested battery life on CF v1.2 with no extras, running at 1.3A for a K2 green (with a 36mm speaker, volume POT at a "normal" average setting). It lasted like 3.5 hours and I finally got sick of testing and shut it off. :P

Malaki Skywalker
07-30-2008, 12:38 PM
Awesome :cool: Its an 800mAh pack in the store... so that means 0.8 hours with a 1A draw? LOL. Doesn't a higher V pack add a bit extra to the run times? :?

Novastar
07-30-2008, 03:07 PM
If you have a driver that does "step-down" conversion, then--yes--higher voltage can yield longer runtimes.

But... that depends on the fwd voltage required to run your LED. Obviously.

Malaki Skywalker
07-30-2008, 03:13 PM
Phew. Well I'm running Lux III's (R-Blue, Red, Red-O and Cyan) w/ a CF v3.0 (Once its fixed), So their fwd Voltages are all Identical, so is it looking good? :)

Thanks Nova! :D

Eandori
07-30-2008, 05:30 PM
All I will add is that Eandori is right (to a point) about the Amp draw from NiMh cells being better... but... here's what you can do with Li-Ions if need be:

18650 cells:

3.6v single cell setups = some can draw up to 3.5A or 4.2A (but I've actually seen one allow 8.5A draw, yes, 8.5A draw)

7.2v double cell setups = some can draw up to 5A (others limit to 4.2A... for some reason I don't see many allowing a higher draw)

11.1v triple cell setups =

32600 cells (big darn cells, essentially "C" or "D" cells):

3.7v -- you can draw something like 16A on a cell I've seen that is out there and available for purchase.

32650s -- same deal, 16A draw is ok.

I'm not 100% sure of everything out there, but... it seems clear that you can draw a decent amount of amps from Li-Ion if you really needed to do so. All depends on the cell type and if a polyswitch is limiting things, and what the PCB is also doing. Still... it can be dangerous (as with all cells), so be careful.

To a point? Nothing I said was wrong.

Nova, be careful. You keep reccomending stuff to newbies when you have people with industry experience constantly telling you to avoid it. The technology of Lithium Ion is not made for high current draw. It's made for max runtime. You can get around that limitation by adding cells in parallel, using "fatter" Li-Ion cells, etc. But still you need to be very careful when you reccomend this stuff to newbies.

Li-Ion, and Li-Po CAN and DO explode when used wrong. Something sharp puncturing the cell wall and shorting the cell can easily lead to explosion. So can undercharge/overcharge (which is WHY there's a small electronic board on them...) Finally, too much current being yanked out of them is very hard on those cells. Laptop's use Li-Ion, but ever notice how quickly your laptop battery needs to be replaced? they are being over-driven. Running an 18650 at 4A or more is overdriving it. Just because the board will let you do it, does not mean you should.

So note... I did say Li-Ion is the "best" for sabers. But it must be used correctly. How would you feel if some novice saber builder had an accident and their 4 year old kid who was smashing the saber into stuff got seriously hurt?

I'm done trying to convince you on this subject. I've said this stuff a few times and it apparently hasn't made an impact. Keep in mind who your target audience is, and what their skill level is when you make general reccomendations!

These sections are quoted from WikiPedia http://en.wikipedia.org/wiki/Lithium_ion_battery

Li-ion batteries are not as durable as nickel metal hydride or nickel-cadmium designs and can be extremely dangerous if mistreated. They are usually more expensive.

Li-ion chemistry is not as safe as nickel metal hydride or nickel-cadmium, and a Li-ion cell requires several mandatory safety devices to be built in before it can be considered safe for use outside of a laboratory. These are: shut-down separator (for overtemperature), tear-away tab (for internal pressure), vent (pressure relief), and thermal interrupt (overcurrent/overcharging).[13] The devices take away useful space inside the cells, and add an additional layer of unreliability. Typically, their action is to permanently and irreversibly disable the cell.

Approximately 1% of Li-ion batteries are the subject of recalls.[19] .

The number of safety features can be compared with that of a nickel metal hydride cell, which only has a hydrogen/oxygen recombination device (preventing damage due to mild overcharging) and a back-up pressure valve


Safety:
Lithium-ion batteries can rupture, ignite, or explode when exposed to high temperature environments, for example in an area that is prone to prolonged direct sunlight.[38] Short-circuiting a Li-ion battery can cause it to ignite or explode, and as such, any attempt to open or modify a Li-ion battery's casing or circuitry is dangerous. Li-ion batteries contain safety devices that protect the cells inside from abuse, and, if damaged, can cause the battery to ignite or explode.

Contaminants inside the cells can defeat these safety devices. For example, the mid-2006 recall of approximately 10 million Sony batteries used in Dell, Sony, Apple, Lenovo/IBM, Panasonic, Toshiba, Hitachi, Fujitsu and Sharp laptops was stated to be as a consequence of internal contamination with metal particles. Under some circumstances, these can pierce the separator, causing the cell to short, rapidly converting all of the energy in the cell to heat resulting in an exothermic oxidizing reaction, increasing the temperature to a few hundred degrees Celsius in a fraction of a second.[39] This causes the neighboring cells to heat up, causing a chain thermal reaction.

Novastar
07-30-2008, 10:08 PM
I'm done trying to convince you on this subject. I've said this stuff a few times and it apparently hasn't made an impact. Keep in mind who your target audience is, and what their skill level is when you make general reccomendations!

Li-Ion batteries are perfectly safe when used under the conditions that are specified from the technology and the specific battery type.

I've used Li-ion 18650 cells for several years now, and had NO problems whatsoever with that line of cells. I am not talking about every Li-Ion under the sun, since... I haven't tested every single Li-Ion cell under the sun. So keep that in mind.

In case people didn't know, Li-Ion cells need to be used with a small PCB (as specified from most places you can purchase from) which controls many aspects of safety, including (but not limited to) over-charge, over-discharge, over-drain, and short circuits.

In many ways, using this PCB actually makes Li-Ions SAFER to use than Alkalines or Ni-Mh cells (which CAN be easily short-circuited comparatively). That's my opinion, however... although Eandori's quote from Wikipedia states otherwise--but then again, it's covering a wide range of Li-Ion cell types (including car cell setups). I've also seen conflicting information on the safety of Li-Ion cells in many places, but there is more to that than simple fact vs. fiction, most of which DOES have to do with the car industry and its loyal factions... but it's not worth de-railing everything to go on about that.

Anyhow, to address what Eandori was quoting Wikipedia on about puncturing the cells or exposing them to strange and undue amounts of heat... well... I don't think it even warrants a response. If anyone is THAT idiotic, they shouldn't be building a saber in the first place. Whoever heard of "puncturing an alkaline" or "putting a ni-mh cell on a stove" or that sort of nonsense, and expecting it to remain safe? Hogwash. Yep... that's just plain stupid.

As to Lithium Polymer, I have not mentioned anything about using Li-Polymer. I presented it as an OPTION in the poll (above), but... I have never recommended it for sabers (or anything else for that matter). I apologize that I didn't include every other type of battery cell in the universe such as Lead-Acid or even give a singular choice for Li-Primary (non-rechargeable). That was silly of me. But I can't edit the poll now--just like I can't edit the saber sound font poll either.

As to novice saber builders allowing their "4-year old to smash the saber into stuff and then getting hurt"... I do not see what that has to do with battery technology, choice, and usage in saber props. People knock over lamps with their sabers, hit one another in the face, step outside and get sunburned, get screwed up in car accidents... so... I really don't see how a discussion about Li-Ion cells could be anymore harmful to someone. Besides... um... are 4-year olds supposed to be using LED sabers? I don't know. Whatever, I'm not an LED saber Nazi.

But as near as I can tell--for us adults... well, I was in more danger of getting hurt at LOOPKICKS this past week than I've *EVER* been compared to using Li-Ion cells. :)

Malaki Skywalker
07-31-2008, 02:33 AM
Cripes... now both you guys have me confused. lol So, Li-Ion, they have the Li-Ion 7.2V pack in the store, I'm very limited on space, so I need to get a small pack in there... IS their a way to prevent such disasters (Who ya calling newbie Eandori :P)

Cheers! :cool:

Hasid Lafre
07-31-2008, 02:43 AM
Iam curious about some things with li-ion packs, Why is it the 14500 the ones tim uses for his packs have such a lower mah than other li-ion packs like the 18650s where they have much higher mah.

I mean one 3.7V 18650 has up to 2600mah in itself.
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=4521

Now I know tim dosent use 18650s cause they cant fit side by side in an mhs.
But how much bigger is a 14500 cell compared to 14650?

What about cr123 type packs? 3V, 680mah per cell? Just how much smaller are they compared to say a AA?

I need a batery pack thats small, about the same size as the 4AA pack bu that has runtimes upwards of mroe than 2 hours or so.

I have read the topic but Iam still lost.

Do-Clo
07-31-2008, 04:47 AM
It is best to do your homework on cell size and electronics before you design your saber, that way you can be sure everything will fit.

xwingband
07-31-2008, 10:02 AM
Cells for li-ion are named with their dimensions (in mm)... I'm pretty sure I've explained this on multiple occasions.

For the format:
XXYYZ

X = diameter
Y = length
Z = shape

Thus, a 14500 (AA size) is 14 mm in diameter, 50 mm in length and a cylinder cell. Now you can see a 14650 is 15 mm longer, etc...

As for safety: That's why when I make li-ion packs I use protected cells. They have the protection pcb built in the cell and make it barely harder than NiMH. As with all thing I have a healthy respect for the danger, but a lot of the junk is hype. If you puncture any battery cells you deserve the danger. If we want to speak of danger puncture a NiMH... no explosion, but I'd keep it away from anyone if you didn't want to get sick.

Hasid Lafre
07-31-2008, 10:15 AM
Thank you much for that xwing. Yes being a complete noob when it comes to any batteries that are not off the shelf store bought batteries, protecting the cells is very important. Considering what kinda money we usually have in our sabers its best to protect the electronics as much as the batteries.

Eandori
07-31-2008, 10:50 AM
If you take a stick of dynamite, pack it in a few feet of foam and smash it into your friends face... it's "safer" then if you hit him in the face with and old shoe.

But if the shoe catches fire, it won't blow your friends freaking face off. So... given a set of circumstances, the shoe was safer.

That's exactly what you have with Li-Ion. They are "safer" until they are used wrong or damaged. At which point, they are much worse. Again, I'm fine with sabersmiths using Li-Ion but they MUST have a healthy respect for safety. Who cares how long you have used them with no adverse effects. All it takes is one person to be badly injured to make all of that lot of wasted advice.


Anyhow, to address what Eandori was quoting Wikipedia on about puncturing the cells or exposing them to strange and undue amounts of heat... well... I don't think it even warrants a response. If anyone is THAT idiotic, they shouldn't be building a saber in the first place. Whoever heard of "puncturing an alkaline" or "putting a ni-mh cell on a stove" or that sort of nonsense, and expecting it to remain safe? Hogwash. Yep... that's just plain stupid.Soldering sometimes results in sharp metal "points" to stick off of things inside your saber. Also, when you drill your saber that sometimes leaves metal burrs that can be very sharp. Or at least sharp edges that could cut into a cell. Perhaps the builder didn't notice them.

Batteries are heavy. They can slide around if not mounted properly. I can easily see a situation where some sharp metal edge either shorts out the cell or punctures it... since we are all building our own stuff... it can happen.

IS their a way to prevent such disasters (Who ya calling newbie Eandori :P) Anybody building their first battery pack or who is very new to subjects like custom electronics construction is a newbie. YOU, and NOVASTAR are not newbies. But Novastar is making posts that WILL be read by newbies. You shouldn't tell people how to use dangerous things... without telling people how they are dangerous so they can avoid the danger. If new saber smiths (newbies...) come here and learn about Lithium Ion batteries, they should also get some warning about using them correctly.

How to use them correctly?
1. Always make sure they have a working electronic board with them. Never use them without that board.
2. Never put them next to something that gets potentially very hot. (above 100 centigrade)
3. Make sure they are well insulated, so they cannot be damaged from sharp edges or metal points. A layer of foam or thick tape around them, secure them in your saber so they don't move around.
4. Use the proper charger for your specific cell pack.
5. Don't draw at or above more current then the cell is rated at. If the cell is rated at 4A max, that's meant for PEAK current. Not MAINTAINED current draw. Sometimes, the circuit board on the cell might also be... stupid. It might allow an 8A draw on an 18650... Don't do that. Know what the expected current rating is of your cell/pack and don't draw more then that.

IF you do all those things correctly... you're fine.
IF you reccomend Li-Ion to people... make sure they understand those points.
IF your audience does not understand that stuff, point them to NiMH.

Think to all the devices you have that already use Li-Ion... Laptop/Cell Phone/GameBoy/PDA/Camera etc. etc. In EVERY ONE OF THOSE CASES, THE BATTERY WAS BUILT IN A PLASTIC CONTAINER MADE JUST FOR THAT PRODUCT. That stops the cell punctures, they already know how hot things get and avoided that design, they control the entire charge/discharge system, and they picked cells that were right for the application. That's not what we have for lightsabers... it's up to the SaberSmith to avoid all those issues. You can't look at Li-Ion and call it "safe" because those products use it... unless YOU take the same steps in your usage. THEN it's "safe."

As a final side note, NiMH comes in many different cell sizes and ratings. So it can sometimes be easier to hit that certain size/voltage/current requirement with NiMH. That's exactly what I found with my Luxeon V LED's... I want an 8.4v battery that's small enough to easily fit in my saber with at least an hour of Runtime. Li-Ion CANNOT hit that list of requirements right now.

Malaki Skywalker
07-31-2008, 11:04 AM
Point very well taken. :shock:

Novastar
07-31-2008, 11:47 AM
Using Li-Ion cells is not akin to using a stick of dynamite... and I don't think using Ni-Mh cells are akin to using an old shoe.

Both cell types are perfectly safe if used properly. As are Alkalines. Although I've seen more problems with alkalines (corrosion, explosion, heat) in my day than I've yet seen with Li-Ion.

Darth Leximus
07-31-2008, 12:19 PM
Does this make anybody else think of...

CLASH OF THE TITANS

::insert old school dramatic fight music::

Eandori
07-31-2008, 01:34 PM
Using Li-Ion cells is not akin to using a stick of dynamite... and I don't think using Ni-Mh cells are akin to using an old shoe.
The example was given to illustrate a point. The point is that Li-Ion is only "safer" as long as you don't go into an oxidization-runaway chemical reaction, resulting in a high temperature and chemical spewing explosion.


Both cell types are perfectly safe if used properly. As are Alkalines. Although I've seen more problems with alkalines (corrosion, explosion, heat) in my day than I've yet seen with Li-Ion.
Agreed 100% Key statement "if used properly" Which is exactly why I'm pushing you to not reccomend Li-Ion without also talking about what MUST happen to keep them safe. Gasoline is also safe... when used properly. So we cannot tell people to use gas in custom-home projects without also telling them the steps to be safe with it.

The steps to be safe with Li-Ion are listed in my posts above. Direct-driving components with no biasing resistance, dumping 8A out of an 18650 Li-Ion cell, running Li-Ion without a verified working regulator board, and using Li-Ion cells without the proper insulation/protection inside a saber are all examples of things that are ill-advised. They will work sometimes, then something else small changes and it all goes to hell.

Eandori
07-31-2008, 02:30 PM
One more quick note... just so nobody is wondering...

I have lots of respect for Novastar. He's a huge benefit to this community and I'm really glad he spends his time with us here. I've had the pleasure of speaking with him on the phone and meeting in person to. Cool guy. I don't want people to walk away from this thinking that he and I are negative in some way. We just debate back and forth sometimes about stuff.

So I stand by the message in my comments, but Novastar. Please don't be frustrated with me for saying them. Let's just keep it safe and help guys coming here to master their art, instead of just tampering with it :)

gundamaniac
07-31-2008, 10:41 PM
I'm not quite sure what the "debate" is all about actually. It seems that Nova really favors the Li-Ion technology and does understand the inherent risks with the tech. When he recommends them to people he probably doesn't regurgitate every safety concern because there's a certain amount of common sense that he probably expects people to have (ie basic battery care, don't puncture the cell, protect against impact, keep away from heat, etc). Aside from the basics, everyone is recommending the use of Li-Ions with PCBs in place, noting the extremely high danger of using a plain Li-Ion cell without a regulator board whenever the use of Li-Ions is recommended to someone.

It just seems to me that Eandori and Nova are both saying very similar things while not quite connecting with each other. "Li-Ions are great for saber-building provided you use them safely and properly" is the vibe that I'm getting from all y'all...right? I understand the concern Eandori has for the safety of "newbies" who are looking into possible power sources for their first projects, but all the same I don't believe Nova has to regurgitate the safety facts and data sheets for Li-Ions each time he mentions them.

These last couple pages of discussion have really been kind of silly. Agree to agree folks? that (and i know i'm repeating this for the nth time, but whatever) li-ions are good batteries, just use them properly!

Novastar
07-31-2008, 11:30 PM
Oh me, I'm not frustrated, heheh! :) I think everyone knows that.

As to the discussion of Li-Ions being silly or anything... welllll, I dunno, I think it's relevant and good as long as it is helping others to be aware. Edwin and I do not have to agree (or even disagree) on anything nor everything in order to raise awareness. Personally, I think it's a GOOD thing that Eandori is basically causing people to THINK and yes, use that GREY MATTER prior to making decisions about cells.

As a matter of note, my initial post on this (back in April '07) pretty much covers what is being said... as the very first response (by Countdown if anyone remembers him) was quite a good way to give a BAD REP to Li-Ion cells. Countdown showed a video of a Li-Polymer cell (or cells) being purposely abused. Thus: it (or they) exploded.

But that isn't surprising now is it? I mean... REALLY. Come on. :)
.
.
.
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[/begin derailment] Wow, it's hard for me to believe that only one year has passed since I wired up a VERSION ONE POINT TWO (v1.2) CF!! Actually two of 'em! So even though it seems as if CF v3 has been around forever... hah. Get some perspective everyone! [/derailment]

Eandori
07-31-2008, 11:54 PM
It just seems to me that Eandori and Nova are both saying very similar things while not quite connecting with each other. "Li-Ions are great for saber-building provided you use them safely and properly" is the vibe that I'm getting from all y'all...right? I understand the concern Eandori has for the safety of "newbies" who are looking into possible power sources for their first projects, but all the same I don't believe Nova has to regurgitate the safety facts and data sheets for Li-Ions each time he mentions them.
Well, no.

Novastar has reccomended things quite a few times that are either borderline, or with simple changes end up being bad. I pointed those things out earlier in the thread then spoke about why they are bad.

So yes... we both agree Li-Ion are best for Luxeon sabers. Yes, I believe that a post specifically talking about which battery is better should call out the proper usage. Because people can, and will use it like a one stop shop. I don't think you need to call out safety usage each time no... that would be silly. But this thread IS the proper place to discuss that. It's entirely about batteries, what is better, and how they work.

Novastar
08-01-2008, 12:19 AM
Me, I just want to know that one dude or dudette who voted for Li-Polymer (?!?!?!!) up there in the poll... :)

:confused:

Novastar
10-28-2008, 12:22 AM
It just occurred to me that with the upcoming release of Ultrasound, Crystal Focus and that sort of thing... if anyone plans to wire up their own Li-Ion cells from scratch, there is a little "bonus" tutorial on wiring up a Li-Ion PCB in the Crystal Focus Wiring Guide (vid IV) I created:

http://youtube.com/watch?v=DNcc2oZWmO8

Specifically, you'll need to "fast forward" to about 7:23.

Hope it helps anyone who has some trepidation about wiring up a specific setup for Li-Ions for their saber projects.

Oh, and while I'm here... keep in mind that the allowed amp draw from most of the decent Li-Ions (for example 18650 cells) is MORE than enough for your standard high-flux/power LED saber. In other words, most any of them can easily handle a draw of 1A or 2A... and most of them can output a brief "flash" of 3A or 4A as well.

Take care all... and have a Happy Halloween! :cool:

MoonDragn
10-28-2008, 07:27 AM
Thanks for that video Novastar. I was going to hook up my own 18650s I brought from batteryspace. They had the 2 18650s in series pack but you had to buy a minimum order of 5. So I picked up the 7.4V protection pcb, the fuel gauge, poly switch, and 2 cells to build my own pack.

The center of my saber where I'm going to be putting the cells is actually a flashlight tube with a inner diameter of 1.1 inches. thats just barely bigger than these batteries. Would I have problems hooking the pcb to them and getting it to fit inside the tube?

Also, the neutral center lead, is that just for recharging purposes? I am guessing so the circuit can recharge each cell separately? Am I right or wrong?

Here is the stuff I ordered. Do you use a poly switch in yours? I'm supposed to wire that switch between the two cells, but how do you do that if between the two cells are both wired to the neutral on the pcb?



Fuel Gauge for PCB of 7.4v Li-Ion Battery Pack (2 cells pack)

Part#: PCB-2GS

Manufacturer Part#: max

(Qty: 1 x $3.99)



PCB with with Fuel Guage Socket for 7.4V Li-Ion Battery Pack (2 cells with 8A limit)

Part#: PCB-S2A8Sq-GS

(Qty: 1 x $3.95)



Li-ion 18650 Cylindrical Rechargeable Cell: 3.7V 2200mAh -- Made in China
with Pre-Wired Tabs

Part#: LC-18650H2-tab

Manufacturer Part#: Lc

(Qty: 2 x $7.20)



PolySwitch 200 --- 2Amp limit

Part#: Poly-sw-200

(Qty: 1 x $1.09)



Connector: A Pair of Tamiya Connectors ( Male + Female ) for Battery Pack

Part#: CN-TMMLFM

Manufacturer Part#: 0

(Qty: 1 x $2.95)

Novastar
10-28-2008, 10:24 PM
Moon, if you're planning to fit two 18650s side by side within a tube that has a 1.1" inner diameter--it will not be possible. Side by side ("double barrel shotgun style") barely fits within a 1.5" sink tube (inner diameter something like 1.35 or whatever). And when I mean barely--I do mean BARELY. You need the "right" 1.5" tube too.

What else... let's see... you said "neutral center lead". I have no idea what you're talking about... :D :D If you're referring to what I'm showing in the video--all of the solder pads on the PCB are used, so... maybe you need to watch from 7:23 forward... CAREFULLY. If you just brush over it--you'll miss what's going on.

For the record/others reading, the video shows wiring a PCB for getting a 7.2v result from two Li-Ion cells (thus, doubling voltage)--so it is NOT for a 3.6v (to double the mAh rating).

Finally, regarding the polyswitch... I could be wrong, but it may already be included on the PCB shown in the video. I've certainly never wired up a secondary chip/control part/extra PCB to Lithium Ion cells before.

Novastar
03-14-2009, 03:35 PM
I'm curious to see how newer folks have been dealing with their sabers and battery choices. Anyone new looking into Li-Ion?

Some of the advantages are listed on the very first post in this thread if you're interested in learning more.

I just picked up two new 2600mAh packs, so... I can't wait to test them out more extensively.

Master Dru-Er
03-14-2009, 05:13 PM
I've been. Made my own trustfire 7.2 1800 mah pack. And have an 18650 pack that was for one project but is being conserved for another. All have worked great. Really needed that voltage to power those lux 5's. It's a no-brainer if your build requires brightness and you don't want an extremely long hilt.

DragonStar
03-17-2009, 04:33 PM
I used a single Trustfire 18650 to power my first saber, which included:

Cree XR-E LED
2 3.6v accent LEDs
Hasbro board

So far so good. I haven't recharged it yet.

xeno
04-22-2009, 07:58 PM
has any one use the 26500 li-ion?

xwingband
04-23-2009, 10:05 PM
Yes, that's "C" size. I use them if they fit. Not very often it does... :/

Novastar
11-04-2009, 04:36 AM
Okey dokey, I'm somewhat "necro-posting" with this, but I thought I'd share an experience regarding Li-Ions vs. Alkalines that really reminded me that using these in my sabers... has saved me TONS of $$$.

Grayven made a curved hilt, RGB, MR-board driven, 7-color changer saber for me some time ago. Awesome! :) The thing has always been a lot of fun, and the kids @ parties/events love the way it can be red, blue, purple, pink, sky blue, and green.

But that isn't the point. The point is... it ran on 4AAA cells...

Now at first, this didn't seem like a big deal... but over time--buying AAA cells for that thing has cost me quite a bit of coin! It sounds surprising, but when I've now bought 2 or 3 "Costco" packs of AAA cells (it's the only AAA saber I own, and I don't use AAA for anything else)... I've spent essentially--I don't know--$20 or $30?? Maybe less, but... here's where we're going...

First off--when the AAA cells start to lose power... the RGB mixtures start to get "wonky" (as X-Wing would say). Yellow begins to look orange... which is NICE... but... the other colors completely flip out, lol. The sound also (of course) starts to sound "sick", heheh...

Secondly--since I've only had the saber for... what... a year? I've now spent $20-$30 in batteries... and the time invested to keep changing them out--often which occurs during an event. I never know when they're going to give out, naturally.

Now...

I recently changed the 4AAA to a single 3.7v Li-Ion 2600mAh 18650 cell. It looks great--the voltage difference isn't really affecting the colors--because the CURRENT is flowing just fine... and so it appears to be a good change.

But here are the real advantages:

* More space in the hilt now--the single Li-Ion takes less overall space than the AAA spring pack... even with the 2.1mm charge port added!!
* "Flatter" discharge curve... meaning we won't be seeing a "color shift" until the cell has about 10 minutes of runtime left
* Longer runtime overall vs. the little 4AAA cells
* Ability to spit out well over 1A of current... instead of the AAA cells barely being able to provide what was needed
* The Li-Ion cell cost only $8.00. When you couple that with the FACT that I have other sabers made in 2005 that have NEVER had their Li-Ion cell replaced (and still aren't showing signs of decreased runtimes)... you have a no-brainer solution here!
* PCB protects from shorts and other problems
* I can charge the saber before every event--always knowing the general runtime I'll be getting
* Better for the environment because I won't be disposing of nasty alkaline cells all the time... and Li-Ion is "greener" overall for disposal!
* I don't have to fidget around trying to find or pack extra AAA cells in my saber bags... nor do I have to stop everything to swap them out.

And if all THAT wasn't convincing enough... just focus on:

$8.00 for one cell... which lasts >4 years it seems... + longer runtime
vs.
$20-$30 for TONS of cells... over a period of 1 year... replacing cells all the time, tossing the bad ones back into the earth.

There ya go. I'll get off the soap-box, but... really. I'm beginning to be of the opinion that NO ONE should be using alkalines for sabers unless the things are just super super basic, used very rarely, and used for short periods of time... :)

Rhyen Skytracker
11-04-2009, 08:01 AM
OUCH!!! Quit twisting my arm already!!! LOL Sold! I am going to try using some Li-Ions in my next few sabers. Thanks Nova.

cardcollector
11-04-2009, 08:41 AM
$8.00 for one cell... which lasts >4 years it seems... + longer runtime
vs.
$20-$30 for TONS of cells... over a period of 1 year... replacing cells all the time, tossing the bad ones back into the earth.



You also have to inlcude the one-time cost of the charger which is around, what? $30

And the recharge port, and the adapter...

I haven't done a recharge system yet just because it will cost around $60 by the time it is over and done with....

But it seems like the way to go!

Novastar
11-04-2009, 03:47 PM
Good point, Collector... let's see...

* Chargers I bought were multi-chargers, ~$20.
* I like these because they handle 4 voltages, and you can create quick-disconnects for many types of plugs/ports... and leave them be until they are done... no risk of fire/problems in general
* You don't have to have fancy chargers... you can do it for less $$ if you know what you're doing with a dedicated, adjustable power supply.

* Charge port is like ~$2.00. Literally. I just bought some.
* Charge jack is like ~$0.50. Literally. I just bought some.

Every time you want to add a port/jack to a saber... yup... that's added cost of ~$3.00 let's say. So we're still talking ~$12 for "forever" vs. $20 to $30 every few months.

Now it's true that once you have one charger... and you build more Li-Ion sabers... you tend to need/want more chargers (depending on your usage). I, for example, often need to charge my sabers the night before an event...

And thus, I need several chargers. That *IS* a downfall of rechargeables... duuuuhhhh, they need to RECHARGE, and this takes a good amount of time. With Alkalines, you can swap them as often as you need.

Word to the wise: Do Not Fall for those "quick chargers". They will save you time, but they tend to feed TOO much current and voltage back into the cell... and this wrecks the battery life over time.

Most Li-Ion cells I use (18650) take at least 4 hours to recharge when they are very low. That may sound bad... but no--it's a good thing.

In general, Li-Ion cells are all about CCCV (Constant Current, Constant Voltage). I may be wrong, but I think they charge @1A pretty well, and of course the voltage is a "bit more" than their rated voltage. So 3.7v cell charges @ 4.2v.

You can use a dedicated power supply to do this if you like... or just spend a whopping $20 and have a charger.

cardcollector
11-04-2009, 05:49 PM
Ok, another Question...

I've read a lot about Nimh and Li-on's, but Which is really better?

Is it a personal opinion thing??

Because I'd really like to buy all the recharge stuff from Tim...

obi-one
11-05-2009, 12:46 AM
I don't understand, how can Li-ion batts outrun NiMH if they are rated practically both the same, 900mAH and 1000mAH respectively (even a bit more for NiMH)

Anyway, where do you get those thousands-mAH Li-ion batteries??? I can only see in the store 900mAH AA

Regards

Rhyen Skytracker
11-05-2009, 06:11 AM
The mAh rating is exaggerated by alot of vendors. We need someone to build 2 test sabers exactly the same, except for the batteries of course, and put Li-Ions in one and NiMh in the other one. (with the same mAh rating) Then we can see which one last longer. (No, I am not volunteering) LOL

obi-one
11-05-2009, 07:02 PM
It's kind of impossible to do that because they deliver different voltage, so from certain point of view, I could say they are intented for different leds.

Four NiMH will light up a Lux III but not a V. And Two Li-ion will light up a V, but if you try them with a Lux III, there will be a lot of energy wasted in the load resistor in form of heat.

Still you could try that configuration, although not exactly the same, it' kinda the equivalent - four Ni-MH with a Lux III and two Li-ion with a V. But in the end the experiment would be useless, because even if you found out which one last more, you wouldn't be able to switch them for use the led of your choice.

I might be interested in doing the experiment, just for curiosity. But can't say for sure if I will... I mean, I would have to buy two charger, it's too much money =P

Novastar
11-06-2009, 01:08 AM
The very first post of my thread will explain some advantages and disadvantages of Li-Ion cells. There are ALWAYS "+" and "-" with which to deal.

That being said:

A single Li-Ion cell (average ~3.7v) is perfect for a single Lux III Green, Blue, Cyan, White, Royal Blue, etc.

A single Li-Ion cell is fine for a Red, red-o and amber... if you merely add a basic resistor (1ohm or 2ohm, 1w cap)

Two Li-Ions (average ~7.2v) are perfect for a Luxeon V.

It's true that when you take a driver board running such LEDs into consideration... it's nicer to have just a bit more overall voltage... but... that's life. Deal with it.

As to Rhyen's thoughts on exaggerated data sheets... well, sure they all have different ways to make sales... but the fact is... a "2000 - 2600mAh" cell that is 18650 Li-Ion will always outperform any cell rated @ 900mAh or 1000mAh or 1200mAh.

The runtime can become irrelevant though if you match battery sizes... and even so... the nice thing about Li-Ions is... they maintain voltage far throughout a charge cycle. Unlike most other cell types.

A disadvantage? Li-Ions are only meant to draw something like 2A to MAYBE 4A continuously. Ni-Mh cells can draw TONS more without issue.

Granted... that's not much of an issue at present (most sabers never need more than 1.5A--if that)... but it may become a future concern.

Eco
11-06-2009, 09:29 AM
Okay, I've had this idea kickin' around for a while.

Can one use a 2.1mm male power jack to create a portable charge station?
Like a couple 18650's wired in parallel to the charge port with a resistor and active LED to charge the main batteries?

Novastar
11-06-2009, 03:46 PM
You're losing me. I read what you said a few times... but I don't think I get it. Unless the idea is simply an "in-hilt recharge" system. In which the answer is YES, and it's been out there for years.

If you mean to say you'd like a little LED to light up while recharging the cells... the chargers generally already have this...

If you mean to say you'd like to use BATTERIES to charge the batteries IN THE HILT... ... what the heck???!? Am I high for interpreting it like that?!?! And if I'm NOT on cold hard crack cocaine... why in the WORLD would you want to use cells to charge other cells? It's a bad idea.

Anyhow. I'm going with the idea that you want to do a jack and port system to recharge. So in general:

* Jack... MALE end for charger... can be many types, but 2.1mm is a good example
* Port... FEMALE end for saber/in hilt... can be many types, but 2.1mm is a good example
* Make sure cell types & charger are the same... make sure voltage & current needs are the same.
* If you like, make the jack/male/charger end setup on quick-disconnects so that it can facilitate any charge (jack/port) setup you have.

Rhyen Skytracker
11-06-2009, 03:55 PM
I think the idea is being able to have a way to charge the batteries in the hilt when there is no 120 V ac for the charger. If that is the case, the zenner diode would probably have to be added to make sure the current only flows in one direction until the source battery voltage drops below a certain amount. I think that is how they work. It would be a good idea to have a way to charge your batteries when there is no where to plug in the charger.

Novastar
11-06-2009, 07:15 PM
Ok Ryhen, I got you... and you're right--heck yah you'd want the zener diode. Problems might be:

* Over-draw/drain... the "full" cells could feed the empty cells too quickly
* Once the voltage drops a bit from the "full" cells... I'm not sure what the relationship would be once the "empty" cells got a decent amount of juice. Things might not flow into the more empty cells anymore
* Pack has to match the saber (duh)... which means you have an extra set of cells...

...so my thoughts are... WHY not just have your cell pack on a quick-disconnect setup... put the new cells in, and set the others aside? Besides all that... where would people be using sabers *extensively*... with no access to any kind of power outlet?

Also, I can't publicly advocate charging cells in an unorthodox manner unless people know *exactly* (and I mean exactly) what they are doing. Even charging cells with a dedicated power supply can be dangerous if you don't monitor things closely and pay attention.

Finally, I have yet to encounter an event where I've needed to use my saber SO MUCH... that the cells are totally emptied. Even if it was some "convention"... I doubt you'd have your saber on the entire time, non-stop... and at the end of the day--back to your hotel/home/whatever and charge up or swap out.

I don't mean to be so obtuse on this but... it's just a risky idea unless you know PRECISELY what you're doing. And there are much easier, more effective solutions.

Rhyen Skytracker
11-07-2009, 12:24 AM
It would be nice to have an emergency power supply where you don't have to take your saber apart to change batteries. Eco has gotten me thinking about this now. I know there would not be many times you need it but just like most other things we do, we do it because we can. LOL I am thinking we could make some kind of box with the zenner diode and any other part of the safety circuit in it and have a plug coming out of both sides of it, one side is the source and one side is the low battery in the saber. All you would have to do it plug the source battery in one side and the recharge port of the saber in the other side. The safety circuit could have a LED that would indicate when the source battery is low and the charging has stopped. I think that is what Eco was talking about, if not it seems like a good idea to me. Thanks for your input Novastar.

Eco
11-07-2009, 05:15 PM
Sounds like you two have interpreted my question quite correctly. Lol

What makes me bring this up is that at Star Wars in Concert, the batteries I was using in one of my sabers went kaput and I had to change them out on a condiment counter amidst a captive crowd of people oggling our TCSS sabers.

Granted, they were alkalines, but the saber does have a recharge port wired in, so as soon as I have the money, I'll be ordering some NiMHs.

The idea is if you can make a charging unit that you can carry on your belt, you can hang the saber from your covertec clip and plug it in, while still being able to move about. (I had two sabers with me, so I would still be able to do show off to the crowd. :D)

And, Like Ryhen said, if we can do it, that's good enough for me! :mrgreen:

Novastar
11-08-2009, 01:08 AM
Fair enough! :) And I *like* people who stand up to a differing point of view with some good reasoning...

So, ok, ok, fair enough... I can see the possible dilemma of wanting to just keeping moving about at an event, no time to swap cells and/or the idea might be that it's cheaper to drain energy from one pack to another vs. buying a new pack.

sithlordfaust
11-08-2009, 03:46 PM
the problem with the belt charger idea is that the Li-ions need to charge at a certain rate for safety. like 500 mah i think. I doubt a protected pack would work this way. I think as soon as you plugged the belt charger in, the protective circuit woul kick the battery pack off and it wouldnt opperate until it was plugged into a proper charger. you could do a pack without the protective circuit but then youd lose those benefits and potentially gain safety hazards.

it is a good Idea. but unil a vendor comes out with one that has the proper protective output, I think its not in our interest to temp fate

Jay-gon Jinn
11-12-2009, 12:12 PM
I've seen emergency chargers for cell phones that use two AA's to recharge a Li-ion cell phone battery....not sure if it would work well as a saber re-charger though.

Kant Lavar
11-12-2009, 06:26 PM
I don't know how effective that would be, given the voltage and amperage difference between, say, two AAs and two 14500s, for example. Although, I wonder what would happen if you took one and soldered in, say, an 18650 pack on a quick disconnect (for recharging) as the power supply. (My gut says "magic smoke" but if it didn't do that, there could be... possibilities.)

cardcollector
11-15-2009, 11:43 AM
I have found that there are lots of different sizes of Li-ion batteries...

What size do you guys prefer? The larger cell with more Mah, or the smallerones with less mah?

Rhyen Skytracker
11-15-2009, 11:46 AM
It depends on the application. You usually want the most mAh (at the correct voltage you need) that will fit in the hilt with the rest of the electronics.

Novastar
11-16-2009, 12:45 AM
Card--I don't want to be harsh (again?) but this is something you can determine on your own with very little thought and logic.

When you get right down to it--EVERYONE would like a cell setup with 83273278mAh... heck... how about 83273278Ah??? :)

But as with everything in life--capacity is limited, and physical space usually governs that limit.

Just like with a container of water: a 9 gallon tank/bottle... is far easier to fit into a fridge than a 2 gallon one. Thing is... well... DUHHH, the 9 gallon container will prevent thirst a LOT longer, hahah.

I suppose a good set of comments I could make would be:

* Li-Ion is among the most lightweight of all cells (Lithium is the lightest metal on the periodic table of elements)
* Li-Ion cells have a very high "energy density". This relates to how much power is packed into each square mm or whatever. More bang for your buck.
* ~3.7v per cell vs. 1.2 or 1.5v per cell of equivalent size can be a no-brainer: with the right driver... excess voltage can be "converted" into current.
* Flatter discharge curve. Li-Ions tend to maintain voltage and current output until they are literally "about to die" (for one discharge cycle). Other mainstream cells are very unlike this.
* HOWEVER... Li-Ions have some limitations on MAXIMUM current output. For example, most Li-Ions aren't ideal for >4A of output. However, Ni-Mh can output MUCH more than this (10A, no problem... 20A--maybe too!). I learned this from Eandori about the Ni-Mh, btw.

Although some of the above is in my initial post... all of the information can be used to understand that even battery chemistry can play into what battery solution you should use.

An example. You will be using your saber basically 24-7. Very often. You'll have it on constantly. Alkaline (1.5v) cells might be your best option, since you'll want to replace them the moment the saber shows signs of "dying".

Another example. Your saber is really crazy unique. It needs "spikes" of 4A, sometimes 5A fairly often, since you're using some bizarre and insane lighting system, and a 2" wide blade. Voltage requirements are high too... but you also want the cells to be smallform with decent runtimes. Ni-Mh may be the best choice, using AA-sized or even AAA-sized cells. Edwin (Eandori) once used 21 AAA cells (yes, that's right: twenty-one) to power one of his CF sabers. It fit in a length of 6" and a width of ~1.35". The voltage was ~13v... which Edwin stepped down to ~11v so that CF could handle it.

Another example. Your saber is SMALL. You BARELY have anyroom left. Yet... you want a simple solution. Not many connections/wires... and you have a VERY tight overall outer diameter--like 1.25" or less. A single Li-Ion cell may be your best bet.

So... ultimately, the decision comes down to planning, making educated decisions... and weighing advantages/disadvantages. No cell is "perfect". Some are close, IMHO (lol)... but none are the end-all, be-all of power solutions.

cardcollector
11-16-2009, 07:41 AM
That's OK Nova, I didn't take any of your posts helping me as harsh. (though maybe I should have:rolleyes:)

That's what I really wanted to know- If there was a cell for any hilt, any time, any where. Obviously now I see there isn't.

I'm also starting to realize that you can't make a " general list" for every saber you make because of the LED differences, hilt size, design, etc.
I've only built three "real" sabers, (two of which are broken right now) so I'm still just trying to figure out the art and difficulty of electronics.

So, I'll try to start thinking on my own more. But I also like to know what the "veterans" do and how they do it, so as to save me (and others) from making costly mistakes.

Rhyen Skytracker
11-16-2009, 08:53 AM
the problem with the belt charger idea is that the Li-ions need to charge at a certain rate for safety. like 500 mah i think. I doubt a protected pack would work this way. I think as soon as you plugged the belt charger in, the protective circuit woul kick the battery pack off and it wouldnt opperate until it was plugged into a proper charger. you could do a pack without the protective circuit but then youd lose those benefits and potentially gain safety hazards.

it is a good Idea. but unil a vendor comes out with one that has the proper protective output, I think its not in our interest to temp fate


It would not be just hooking one set of batteries to another. We could need a power regulating circuit with a zener diode in it. The zener diode circuit would restrict the amount of current flowing to the receiving batteries too. So as long as the source batteries are above a certain voltage (the battery pack PCB would cut the batteries off below a certain voltage) then the regulated current passing through the zener circuit would charge the receiving batteries.

Kant Lavar
11-16-2009, 01:38 PM
That's one of the reasons I liked Jay's idea about the cell phone charger. Most if not all cell phone batteries are li-ion cells, so I would imagine that a cell phone charger would want to pump its power at that 500 mA target. The big question in my mind, since cell phone batteries are 3.7 volt cells, is will the voltage be an issue in recharging, say, a 7.4v pack?

Well, that, and would the charger's electronics survive replacing the power supply with another 7.4v pack, but again, I see no real way to test that short of plugging a battery into it and seeing what happens.

Novastar
11-16-2009, 03:50 PM
I'm still going to advise against trying experiments with this unless you absolutely know what you're doing... but let's see:

* Yes, many cell phones are on Li-Ion... they have been for years! :)
* Li-Ion generally only work with PCBs controlling over-current, over-discharge, low voltage, etc. So, they WOULD have a form of regulation circuit
* The zener diode would be very important
* Yes... using a 7.2v pack to "charge" a 3.6v pack would likely be trouble... even despite the PCB protections and a zener diode. I don't know this for a fact, so I'm erring on the side of caution.

We don't want to encourage any n00bz to try things like this without EXPLICIT knowledge. Also--it will go back to giving Li-Ions "a bad name" with people. I've seen too many abusive vids where people show how they explode... and we also have some laptop fiascos in the past (due to PCB circuits failing or outright being wired improperly/not included).

Just to be clear: ANY battery cell can be made to explode (for the mostpart). Abuse of a cell type doesn't count as "it's dangerous" to me.

If I set my house on fire... it is likely to become a hazard. DUUUUHHHHH. lol

Eco
11-19-2009, 09:24 AM
Would the concept of using the external pack and zener diode work with a NiMH setup as well, providing the external pack is obviously also NiMH?

I know Nova's kind of the Li-Ion expert, but I don't know if we have a NiMH expert here. Lol

Novastar
11-19-2009, 01:08 PM
I'm definitely no expert, lol. Far from it.

As to NiMh--when you get right down to it, voltage is voltage is voltage is voltage. Sure, cell types differ, but 12v "alkaline" is still essentially 12v "Li-Ion" and so forth. It doesn't mean you should mix battery chemistries... no,no,no... but it DOES mean that the energy is the same.

Now, Ni-Mh have a lot more "output power" than most standard Li-Ion cells. On Li-Ions, the PCB limits the output (~4.2A) to prevent the cells from becoming dangerous. Ni-Mh are different, since in this case they can take a larger strain on output (>5A) for the mostpart.

I learned this from Edwin (Eandori) in the past. He applied Ni-Mh cells in RC-racing, because you could get some CRAZY "boosts" of speed from the cells. Versus using other cell types.

But anyhow... yup, the diode would still need to be there. In fact--maybe MORE SO because of the fact that the cells are made to output a truckload of current if the situation was "wrong enough". Therefore, additionally, you would definitely need more protection on the "charging pack" to put a gate/limit on how much current would be allowed to flow.

When you get right down to it... GENERAL cell charging is something like "CCCV" (constant current, constant voltage). Each cell type differs, which is why you will see "Li-Ion" chargers and "Ni-Mh" chargers and so forth.

If you had a dedicated power supply + the RIGHT KNOWLEDGE... you could recharge most any cell that was made to BE re-charged. Because you could provide the precise CCCV setup.

Anyhow... again--not to be duh pahtee poopuh, but... I am advising *against* making a "battery to battery" charge pack. Not that I think it cannot be done... but only because:

* Honestly, WHEN are you in a situation SO dire... that you can't get to a power outlet with your saber??!? Are you REALLY ~that~ addicted?!??! :D

* When the possibility exists to: A) swap cell packs and have saber running in 10-15 seconds... B) charge current saber with "special batt pack" and wait 4-8 hours... ... ... WHEN in Zeus' holy place in the clouds would you choose option "B"?!?!?!?

* This requires fairly decent electronics knowledge. Also--it's still a dangerous experiment. One wrong move, and ~poof~ ... it's fire time. Possibly explosion time. No bueno.

* My Li-Ion chargers really aren't all THAT much bigger than a battery pack. Sure, they're bigger, but this isn't to say that they are SO horribly "non-portable" that they would come with you to some event with any more difficulty than another battery pack.

Finally, I'd say that maybe waiting for WiLectricity (which is actually already HERE) might be even better, heheh!

Rhyen Skytracker
11-19-2009, 02:41 PM
I say the best thing to do is make another saber. That way you won't have to worry about charging batteries, just grab your other saber. LOL

Kant Lavar
11-19-2009, 05:00 PM
Oh, granted. (Actually, if I really wanted a portable recharging solution for an in-hilt battery pack, my battery charger can run off a car battery!) And personally, I like being able to just swap out Trustfire cells quickly - in fact, when I troop in my Jedi costume (if/when I actually get the belt!) I plan on having an extra pair or two of charged batteries ready to go in one of my belt pouches.

It's just kind of an interesting thought experiment.

Eco
11-20-2009, 09:43 AM
Why make a battery-battery charger?
Because we (theoretically) can. :D

Jay-gon Jinn
11-22-2009, 02:13 PM
Oh, granted. (Actually, if I really wanted a portable recharging solution for an in-hilt battery pack, my battery charger can run off a car battery!) And personally, I like being able to just swap out Trustfire cells quickly - in fact, when I troop in my Jedi costume (if/when I actually get the belt!) I plan on having an extra pair or two of charged batteries ready to go in one of my belt pouches.

It's just kind of an interesting thought experiment.
This is what I do....and if the back up batteries die on me, I usually have 3- 5 back up sabers with me too. ;)

Novastar
02-08-2010, 04:55 AM
A snippet of a recent post I made. I thought it was a fitting thing to add here... for anyone wondering about Lithium Ion cells in general.

I will also note... I don't think Lithium Polymer is a very good idea for sabers. But, I put up the poll a long time ago. Sorry for that! :)

---------------------------------

http://en.wikipedia.org/wiki/Lithium-ion_battery

By the way, here is a bit on Lithium Iron Phosphate cells (LiFePO4).

http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

As a matter of note... Lithium ION cells--don't really even have the metal "Lithium" in there. Because it's in ionic form. You can see this in the above link--it just says it in a more scientific way.

Also, Lithium primary cells... unfortunately ARE using the metallic compound or whatever of Lithium. These shouldn't be confused with Lithium-Ion! :) Although it would be easy for a n00b to do so... :rolleyes:

Finally--although it can be found in the above links--Lithium Ion is a 70's (!) technology... and LiFePO4 is a 90's technology. :) This doesn't mean that Lithium Ion tech is "old school" and out-dated though... it only means that Li-Ion has seen 30 years of (successful) development. And that LiFePO4 still has places to go.

Whether or not LiFePO4 ends up being the "best in show" over Li-Ion remains to be seen. What I think is cool is... new techs and solutions are always changing/improving.

TroyO
02-08-2010, 03:03 PM
It's actually pretty simple to make a charge-on-the-go pack. Get a "12V" charger for 7.4 Lithium Ion packs.. IE:

http://www.batteryspace.com/customizesmartdcchargerfor74vli-ionbatterypackwith55x25mmmalebarrelconnector.aspx

Get a 14.4v NimH (Or Li-Ion, or even use an Alkaline 8-10 pack... or even a 12V sealed lead acid pack, your choice really) pack, such as:

http://www.batteryspace.com/nimhbatterypack144v5000mah6x2xcnimhcells.aspx

or http://www.batteryspace.com/customli-ion18650battery148v4400mah6512whwpcbcu-mm111pid4901.aspx

Gut the one, hook to the other and bingo... you are all set. Because you are powering the charger and not the other pack directly it should work like a charm. You should get about 1.5 to 2 charges of a 7.4v, 2600 mAH Li-Ion pack from it... more or less depending on the pack you get.

Note that charging voltage for a car is 14.4V, although the batteries are nominally "12V"... which means any charger designed to run from car voltage is generally good from about 11V-15V.

So... there ya go. :-) Get a cheap wall charger for the 14.~V pack of choice and you are set to go for less than $150 bones.

Novastar
03-16-2010, 06:30 PM
Not to resurrect the Li-Ion situation, but... here's a question/observation I'm wondering about...

Ok... so you bought your Li-Ion cell/cells. You did this in 2005/2006. So, of course you are expecting that SOMEtime soon enough... the cell(s) will no longer hold (an acceptable) charge...

Have you ever experienced that a cell/setup would:

* Suddenly stop working (even if you check it with a charger)... but after a day or so, you're able to give the sucker a fairly decent charge

* General "flickering" from the cell/pack... even when the saber is NOT set up to flicker (meaning basically the current draw is unable to stay 'stable')

* Obvious decreased runtimes, yes...

Anyhow... just wondering! :) The point of this is--most of us who started using Li-Ion (in sabers)--did so no earlier than 2005 or whatnot... so it makes sense that few people have had their cells SO DARN long that they would already be nearly dead (permanently).

Thoughts/experiences?

Novastar
05-04-2010, 12:00 PM
* BUMP? *

Dang. It figures. I ask ONE question of my own for once and all I get are crickets, hahahahahha :P

May the fourth be with you all... lol

Jay-gon Jinn
05-04-2010, 09:01 PM
I don't have any Li-Ions that old yet, Nova...sorry, can't help you much....

mihunai
05-05-2010, 12:22 AM
Havent used Li-Ions myself, but from what i read, the internal resistance increases over time, causing the battery to fail.


Maintaining a battery at low internal resistance is important, especially with digital devices that require high surge
current, as our printers do. Li-ion offers internal resistance characteristics that are between those of NiMH and
NiCd. Usage does not contribute much to the increase in resistance, but aging does. The typical life span of a Li-ion
battery is two to three years, whether it is used or not. Cool storage and keeping the battery in a partially charged
state when not in use retard the aging process.
The internal resistance of the Li-ion batteries cannot be improved with cycling. The cell oxidation, which causes
high resistance, is non-reversible. The ultimate cause of failure is high internal resistance. Energy may still be
present in the battery, but it can no longer be delivered due to poor conductivity.

http://www.extech.com/printers/resources/case/attachments/08212009.pdf

mTm

Matt Thorn
05-06-2010, 05:18 PM
* BUMP? *

Dang. It figures. I ask ONE question of my own for once and all I get are crickets, hahahahahha :P

May the fourth be with you all... lol
I think any of us would leap at the opportunity to repay you for all the questions you've answered for us, but in this case, I'm thinking that since you were one of the earliest adopters, and probably put more strain on your batteries than the rest of us combined, no one else here is yet qualified to respond intelligently. I take it you asked because you are experiencing those symptoms with some of your oldest li-ion-powered sabers? A quick Google does not turn up much useful information, beyond scads of advice on prolonging li-ion battery life. How reliable that advice is anybody's guess, particularly since some of it is contradictory. Depending on the saber, replacing li-ions could be a major pain, but for someone like you, who can't afford to have a saber go funky on you at a bad time, I'd suggest biting the bullet and replacing those old li-ions with fresh ones. This bland advice brought to you by someone who has trouble even remembering which of his sabers are NiMHs and which are li-ions (and what the voltage of the li-ions in a given saber is). :rolleyes:

sithlordfaust
05-06-2010, 09:12 PM
It's actually pretty simple to make a charge-on-the-go pack. Get a "12V" charger for 7.4 Lithium Ion packs.. IE:

http://www.batteryspace.com/customizesmartdcchargerfor74vli-ionbatterypackwith55x25mmmalebarrelconnector.aspx

Get a 14.4v NimH (Or Li-Ion, or even use an Alkaline 8-10 pack... or even a 12V sealed lead acid pack, your choice really) pack, such as:

http://www.batteryspace.com/nimhbatterypack144v5000mah6x2xcnimhcells.aspx

or http://www.batteryspace.com/customli-ion18650battery148v4400mah6512whwpcbcu-mm111pid4901.aspx

Gut the one, hook to the other and bingo... you are all set. Because you are powering the charger and not the other pack directly it should work like a charm. You should get about 1.5 to 2 charges of a 7.4v, 2600 mAH Li-Ion pack from it... more or less depending on the pack you get.

Note that charging voltage for a car is 14.4V, although the batteries are nominally "12V"... which means any charger designed to run from car voltage is generally good from about 11V-15V.

So... there ya go. :-) Get a cheap wall charger for the 14.~V pack of choice and you are set to go for less than $150 bones.



Car charger might work like this, because like batteries, car chargers run on DC. Wall chargers however work on AC