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View Full Version : Wrong battery for a Fenix TK10?



tomasaur
12-21-2009, 06:55 PM
I apologize if this is a dumb question, but I'm brand new to the world of high end LED flashlights. I just purchased a TK10 and a pack of 3.0 V. lithium batteries online. The batteries, however, say NOT FOR FLASHLIGHT USE in giant letters on the package. They're Ultralast ULCR123-2 batteries. BUT, the Fenix can use 3.0 V Li batteries, so is there some level of battery intensity that I don't know about working here, or is the dire warning on the package trying to keep people from using the batteries in cheaper flashlights?
Thanks in advance,
Tom

ImGeo
12-22-2009, 12:00 PM
Just a thought, but maybe the batteries are not designed for high amperage (because they're cheap batteries, or maybe because they don't use the typical lithium chemistry).

if you have a amp-meter (supports >10 A), you can quickly short the battery (<2 seconds) and see if the battery drains to close to 10A, or if it can only support <2 A. Be careful though! Shorting batteries will heat them up very fast, so don't do it for a long time.

If anyone else disagrees with what I said, please be sure to express it--i don't want anyone getting hurt with a shorted lithium battery.

Niconical
12-22-2009, 12:56 PM
If the batteries are of a lower quality, you could still be ok to use them on the TK10 lower setting, which draws much less current.

In the meantime you can then find some decent quality batteries.

Post here which country you are in, or from which countries/regions you would like to buy, and we can point you in the right direction.

Henk_Lu
12-22-2009, 03:15 PM
I googled those cells, and it seems they are not cheap china-crap and normal CR123A. There exist rechargeables however, with nearly the same denomination. Check the cells, if they are rechargeables, it's written on them.

If they are primaries, I really don't see a reason to not use them in flashlights. CR123A were chosen for flashlights because they can provide a high power drain, much more than Alkalines. It is true however, that some lights with multi-die emitter go also to their limits today, especially in single use. But again, for primaries, this shouldn't be a safety problem.

If they are rechargeables however, things change. You musn't draw more than 2C from a li-ion, which is about 1,5 A for an RCR123. There are indeed lights which draw up to 2,9 A (or even more) and li-ions musn't be used in them, you take either primaries or IMR cells (safe chemistry, but lower capacity). We also tend to forget that there are still incandescent flashlights, depending on what bulb they use, they can draw very high current.

Check your cells and to get better answers on the topic, ask your question on CPF in the battery section!