Lithium AAs OK in Fenix LD12?


Newly Enlightened
Dec 2, 2012
In my searches I've found that "generally" standard AA Lithium batteries (not the rechargeable ion's) are OK in "most" LED lights. I seem to perceive this may not be the case with some LED's however...

I have 5 Fenix lights coming (4 are for gifts) including 3 1x-AA LD12s and the aaa LD01/E01 promo pak. Is it OK to use Lithiums in these specific lights? Anyone doing so?

I've had numerous popped alkaline batteries over the years and hoping I can get away from that problem with the new Fenix LED lights.


Aug 8, 2009
Yes, it is okay to use lithium primaries in those lights. I have used an L1D CE and LD10 with primary lithiums for a bit with no issues (though I vaguely recall losing the low modes for a little while in 2xAA format). 1xAA is no problem because the driver is designed for 3.0 V.

Now here's the issue: The reason why high voltages above driver specifications are not recommended is because without a driver to buck the voltage (especially in 2xAA format, or 1x X format with a lithium ion), you can damage the LED or the driver or both. Often times the light WILL work, but you'll lose the low mode because the light is running in direct drive. But eventually, and sometimes very soon, the light will cease to function, either because of a fried driver or LED because the voltage is just too high. Just because the light works with these batteries for a while does not mean they will work forever, and they are not designed to and often don't after a period of time.

For gifts, I only give people 1 x X formats to avoid issues with mixed capacity batteries and such, and I never use alkaline. For gift lights, I stick in lithium primaries, for my own lights, I run Eneloop for Li-Ion or lithium primary. I never happily choose to run alkaline (well I haven't, but if I'm some day desperate in some kind of emergency and run out of my billion good batteries, I will) and will never gift a light with an alkaline in it, even if it came with one. Hope this answers your question!