Lithium-ion battery packs

[Mike]

Has anybody out there made a LED flashlight using a lithium-ion battery pack? The voltage works nice for powering white LEDs since you get about 3.6+ volts/cell. They can give the extra current needed for powering lots of LEDs and you don't need to worry about the battery cost (after initial purchase) since they are rechargable. See ebay for deals.

I'm looking for a battery pack that uses approximately AA sized batteries so it would work easier with standard flashlights.

 

[RonM]

I've got two 4600mAh Li-Ion battery packs from a defunct camcorder that I'd like to use for an LED flashlight. Strange this is I can't figure out how it works. Has three terminals and I get only fractional voltage across any two. But they power the camcorder just fine. It's a mystery!

RonM

 

[Chris M.]

I definately think they have potential! I have a portable minidisc recorder here that uses a tiny little slim LiIon battery that would power a few white LEDs for ages. 3.6v 700mAH and only 2 3/4 ins long, trouble is they cost a fortune! and it s charged internally through the MD recorder, not a seperate charger.


Has three terminals and I get only fractional voltage across any two. But they power the camcorder just fine. It's a mystery!

There is probably an internal electronic switch that is there to prevent disasterous short-circuits in your bag. Apply the right voltage to the correct terminal and presto- you get your power out. Ideally you`d have to look inside though to see how it was connected and find out if it was possible to remove/bypass it. I wouldn`t like to peel apart expensive LiIon batteries though, maybe there`s another way.....

 

[The_LED_Museum]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by RonM:
I've got two 4600mAh Li-Ion battery packs from a defunct camcorder that I'd like to use for an LED flashlight. Strange this is I can't figure out how it works. Has three terminals and I get only fractional voltage across any two. But they power the camcorder just fine. It's a mystery!<HR></BLOCKQUOTE>

We've been down this road before, and it's apparent my suggestion didn't pan out.

Now I wonder if the terminals need physical pressure on them in order to make a circuit, kind of like the leaf switch in a headphone jack that cuts off the speaker - but this one would connect the battery to the outside world.

$0.02 (for what it's worth, with inflation and all going right now)...

 

[snakebite]

improperly charged/discharged li-ion=incendiary grenade.
very touchy and not safe to experiment with.
i know what i am doing and i havent yet done a li-ion flahlight conversion.

 

[RonM]

Yeah. It's totally frustrating me trying to figure out how to get at the battery's 3.6V. I tried out the various suggestions received from this forum, but no luck. Thanks anyway.