Cell Phone batteries

Has anyone used cell phone batteries to power a light? In particular, the 3.6 V Li-Ion batteries from a nokia. Don't know what the rating is on one of these, but I happen to have a couple laying around with a spare charger. They're pretty small too, about 1 in x 1.5 inches long. I figure they'd make a good power source for LED's.

InTheDark,

I sure have. I have three lanterns made from old motorola batteries, mostly NiMH.
Two are hybrids, with a halogen center lamp, and an LED off to the side. Made from cheap Eveready lanterns.

The way I see it, the batteries were nearly free since I my brother and I got new small cellphones and these monster sized 1800 mah batteries would go to waste anyway.

I have a small one for LED only using the LiIon. They all seem to be very durable and seem to hold a charge fairly well for camping and around the house where carrying weight isn't important.

One warning, though. LiIons tend to have a control chip that prevent them from being over charged or over drained. The NiMH's do not.

About a year ago I experimented with some 2 cell lithium ion cell phone batteries I have. I believe I powered 2 LEDs in series without any added resistance. It worked very well. Packaging it into a flashlight where it is still easy to recharge is the challenge for me.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Mike:
About a year ago I experimented with Packaging it into a flashlight where it is still easy to recharge is the challenge for me.<HR></BLOCKQUOTE>

It is less likely with LEDs, but not impossible: You have to take care that you don't deep discharge the cells.