Fenix E05 on 10440?

Hello, I just got a Fenix E05 and really like the thing on normal AAA's. I find I only use these little lights for a few seconds at a time, so a tiny pocket rocket would be awesome. Question is, can they run on 10440 for short periods (I understand I have to watch the heat)? How long is it safe to run? What kind of runtime can I expect?

The E05 should not be used with 10440 cells. Absolutely not recommended! Why?

- Overvoltage: AAA Alkaline = 1.5 v, 10440 = 4.2v. The electronics will precipitously fail - whether the first usage or the 100th usage, but they will fail far sooner than if the E05 was run on alkalines or the Eveready Lithium cells which run about 1.7v.

- Heat: The E05 uses an optic, not a metal reflector. The 10440 overvoltage will generate a lot of heat from the LED. That heat will discolor if not outright melt the optic.

End discussion.

Yep... don't do it as you will fry it. I read somewhere on here it gets longer run times with a Lithium cell. I am still on my original battery 2 months later. I only use it when I need light though.

think the best you can use is lithium cell which will double the runtime to 5hrs.

The E05 kicks out 27 lumens, so even if you managed to double that by running on 10440 it would still be a lot less than many other AAA sized lights. For example the Olight i3 knocks out 70 lumens and is the same price or cheaper than the E05, and only 6mm longer.

I was speaking from experience. I decided to risk my $22 E05 light to see how it reacted to 10440s. The output did not even double, and the intensity started dropping after about 20-30 seconds of run time on the 10440. I suspect that the optic was discoloring even though the outside of the head was not hot. fried.

Tried putting a 10440 in my e05 today. Did run about twice as bright if not more. Did not run it past a minute though to be safe. Tried it a few times.

I think putting a 10440 in the old Fenix E05 should be avoided, because according to the data sheet of PAM2803, the maximum input voltage to be used is Vf-0.2 V, Vf being the forward voltage of the led. Vf for Cree XP-G is decladed to be between 2.9 V and 3.25 V @ 350 mA. In Fenix E05 i think the LED current is around 95 mA (Rs is 1Ω). As the 10440 voltage can be over 4V there is risk of damage the Fenix E05.

Regards.
Christian

Oooh. That sounds like a bad idea even without looking it up. Maybe on the newer xp-e2 version?

ragweed said:

Yep... don't do it as you will fry it. I read somewhere on here it gets longer run times with a Lithium cell. I am still on my original battery 2 months later. I only use it when I need light though.

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yeah... but...don't forget an energizer L92 lithium primary is rated 1.5V peak 1.7V at most. An "10440" is a lithium secondary rated at 3.7V, peak 4.2V. An energizer L92 has around 1100maH or juice while its alkaline cousin E92 only has 500maH. Thats where the "longer runtime" comes from, twice the capacity

We say 10440 and assume it is a li-ion. 10440 is the ANSI dimension of the battery: 10mm wide 44mm long 0 for cylindrical. That can be spoken for any #4 or AAA size battery and in any chemistry. hopefully that ends the confusion.

martinaee said:

Oooh. That sounds like a bad idea even without looking it up. Maybe on the newer xp-e2 version?

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Vinh has done his work on it. I have an E05SSvn (stainless steel) that does 1200 lumens on a 10440. No joke. That said, it is direct drive only, runtime is only a few minutes, and he has said that 10440 will fry the stock driver immediately. The optics are not a problem, and the light can take the heat, but the driver cannot. Full stop. If you try it, you will most likely have a nice paperweight.

Fenix E05 is banned to use 10440/10450 batteries.