Li-Ion/Polymer 3.6v batteries... your experiences?

[neophyl]

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]

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]

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 .

-Eric

[Novastar]

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]

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]

Coming soon!!!

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

[xwingband]

Yum! Especially the li-ions.

[Novastar]

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]

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]

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.