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Delmustator
12-14-2006, 07:48 PM
I've been reseaching about Li-ION batteries and possibly building a rechargeable saber hilt. My source of batteries is (4) Dell laptop battery packs. All are fairly new.

Each battery brick contains eight Sony Energytec STG US18650GR G3 Li-ION batteries. The entire battery brick is rated at 14.8V 3800mAh or about 1.8V 1300-1600mAh per battery. They are somewhat larger than a standard AA battery but I think (4) of them would fit in a hilt nicely. They also contain a power storage level LED display that is memory cell activated and displays for 3 seconds.

This picture is of the G2 version. Their appearance is the same. The G3 version that I have has higher capacity.

http://www.gearhack.com/Forums/Computer/Notebook/Rebuilding_the_Sony_VAIO_PCGA-BP51_Li-Ion_notebook_battery_pack.files.hidden/Sony%20EnergyTec%20US18650GR.JPG

This is another view of the G4 version. Each cell has a 18mm diameter and is 64.7mm long. Each cell is rated at 3.7V, 1800 mAh.

http://blogs.zdnet.com/images/sony-ibook-battery-1.jpg

This webpage seems to have a lot of info using these batteries with LED applications in flashlights.

http://www.candlepowerforums.com/vb/archive/index.php/f-9-p-34.html

xwingband
12-14-2006, 07:59 PM
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2763

Those 18650's are weak if that's the amperage. The same size above is 800mAh more.

Although they are larger (not a bit, but a lot) you can fit two across in a sinktube. If you have the room four (two across then stacked) would be lots of amperage.

These aren't terribly new either, but whatever...

vortextwist
12-14-2006, 08:19 PM
Are those the ones that are exploding?

Firebird21
12-14-2006, 08:21 PM
Are those the ones that are exploding?



http://www.gaownersclub.com/forum/images/smilies/icon_spit.gif

vortextwist
12-14-2006, 08:22 PM
:lol:

xwingband
12-14-2006, 08:24 PM
Any li-ion you let short can "explode".

vortextwist
12-14-2006, 08:26 PM
yes, but I was just wandering about the batteries they talked about in the dell laptops.

james3
12-14-2006, 08:37 PM
We actually have something good in here. Yay!
I have used a few recharge packs here and there for stuff and I think it is what I am going to do with my personal stuff. I have been looking at the 3 volt stuff so that I can get a lot of bang in a space that we are already used to working with.

Jonitus
12-15-2006, 08:32 AM
Just for curiosities sake, have those of you that have been building rechargeable packs found a decent source for a 2+2 stacked AA or AAA battery holder? I can find lots of 2+2 square holders, but not stacked.

I'm hoping to use a rechargeable pack in my next saber and would really like to get a decent holder that could serve as a mounting point for Erv's board when it comes out.

EDIT - Never mind...checked the store...Tim has 'em. Damn you Tim for always having what we need for building our sabers! Curse you! j/k

LordArgyll
12-28-2006, 08:02 AM
Does anyone have experience with rechargeable Li-Ion CR123s? With driver board, sound, a couple of switches, recharge port and a lot of wiring, I'm rapidly running out of room in my hilt and was thinking about using a couple of these to make a rechargeable pack. I've seen rating on various brands for anywhere between 600maH to 2000maH and was wondering if anyone has experimented with them and might have some insight into their uptime, etc. Thanks.

xwingband
12-28-2006, 08:50 AM
I don't know where you're seeing 2000mah ones, but I expect them to be similar to this in amperage:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2426

My problem is that there isn't a good charger for them that I've seen. They're benifits are marginal too when paralleled. You can get a 18650 that is roughly the same size that gets 2600mah compared to 2 CR123's at around 1400mah.

It's nice that they can be 3V, but otherwise I haven't figured yet how to make them useful in a rechargeable situation with out having something better.

LordArgyll
12-28-2006, 09:10 AM
I was reading an independent review on the Delkin RCR123A over on the CandlePowerForums.

http://www.candlepowerforums.com/vb/printthread.php?t=73460

The battery is supposedly rated at 2000mA but the guy got a reading of 6000mA off of it in a burst.

Unfortunately I can't seem to find the "official" factory specs, but if it's true, they might be useful.

Regarding the 18650s... if one were to build a pack with them (or any Li-Ion for that matter) would you recommend a protection circuit? Or should a "smart" charger be sufficient to minimize the exploding hazard?

xwingband
12-28-2006, 09:45 AM
What they guy is talking about there is 2A of output. That doesn't mean that's the capacity... just that it can put out that much at a time.

So if a 1A battery is outputting 2A then it'll be deader than a door nail in 30 minutes.

As for protection circuits... I've never done them. They are not as much for the exploding as they are to condition the battery well and not expell all of it's power (bad for li-ions).

However since Luxeons will not light after a certain point of voltage I've never had a problem without the PCB protection.

If that review is true and they're putting out that much voltage I wouldn't even bother with them. So far 3V was the only benefit I saw.

LordArgyll
12-28-2006, 09:53 AM
Guess I'll go with the 2600mAh 18650s then. Thanks for your input!

LordArgyll
01-12-2007, 07:20 AM
Wow... so the 18650s are huge. I could see them being useful in a sink tube saber, but as far as an MHS saber is concerned, unless you plan on having a grossly oversized hilt or a direct drive setup, they seem like something to avoid. My saber is a ribbed section with two 2.5" extensions and there's just no room to fix 2x18650s plus driver board and sound and switch wiring.

Well... chalk it up to a lesson learned... measure before you buy. :lol:

Strydur
01-12-2007, 09:30 AM
Yes they are. You could use just one for a 3w or k2 though. You can also get them setup end to end and they would work for a 5w.

xwingband
01-12-2007, 03:21 PM
Yeah, end to end in a ribbed section would work well.

Jedi Ranger
02-17-2007, 12:08 AM
Does anyone know where I might find a stick-form battery holder for 2 of the 18650 cells? I'd like to build a couple packs (either with or without the protection board).

Or...........can anyone give some pointers on building custom 7.2v li-ion packs from (2) 18650 cells. Removable batteries would be best, so I can recharge them faster.

Madcow
02-17-2007, 11:18 AM
I figured that might be a problem.
Juging by your craftsmanship Arg - you'll figure something out.

I had a friend build me packs out of 8 AAA NIMH cells each. (4 cells in series - paralelled to another 4 in series). The end result is a 4.8 volt pack that puts out 2000 mAh, and fits inside 1" ID.
I just measured the voltage on one pack fully charged and it was 5.4 volts! I was expecting no more than 5v. I wonder if my charger is overcharging the pack - or if this is normal...

Any thoughts?

BTW - how do smart chargers detect when the pack is charged?
Mycharger is this one...
http://www.hobbico.com/chargers/hcap0290.html

MC

Firebird21
02-17-2007, 01:57 PM
BTW - how do smart chargers detect when the pack is charged?



Yes, that's what makes them "Smart".

xwingband
02-18-2007, 02:58 PM
BTW - how do smart chargers detect when the pack is charged?



Yes, that's what makes them "Smart".

lol, They stop charging every once and a while to check the voltage.

virus692
02-18-2007, 06:01 PM
I found this cool site from ECN Magazine.
http://www.tadiranbat.com/home.php
they do custom and different batteries.

LordArgyll
02-18-2007, 06:27 PM
I wonder if my charger is overcharging the pack - or if this is normal...

I think it's normal for a fully charged pack to be as much as a volt over its rated charge. That's how smart chargers can tell when the pack is fully charged... when the voltage is higher than the nominal voltage.

Novastar
09-21-2007, 01:27 AM
Something like that. For example, a "3.6"v Li-Ion pack will fully charge and read something like 4.2v.

But, that is the point. Ratings are the AVERAGE of the overall battery voltage. As you use the Li-Ion cell, its voltage will decrease from 4.2v to something akin to 3.3v. By the time it gets to 3.2v or so... the PCB kicks in and closes up shop. This prevents the batteries from dropping so low out-of-sync (if you will)... that they become unusable.

A Li-Ion pack without a PCB is doomed, as once its voltage drops below a certain level... you can kiss it bye bye.