Fenix E12 run time graphs compared with other popular lights

I did a run time test of the E12 at high mode and medium mode. In the high mode, they must really be pushing the current out of a single AA battery as it only lasted 62 minutes. I estimate the lumens to have averaged 150 over that time frame. It's apparent to me that an XP-E2 isn't meant to be driven like an XP-G2 or XM-L.

The medium and low mode is where the E12 really shines as far as efficiency goes. I measure efficiency as the area under the curve (length x width) or output x time. Note from the 2nd graph that it was the 2nd most efficient light at medium mode that I have tested. And that is but a third of all the 1AA lights I have tested. Its output was very steady right up to the battery's end............one of the best I have ever seen. By the way I was using freshly charged Eneloops for the test.

I have to say that I like this light. I would plan to use it mostly on the lower modes knowing that I'd have that high mode if needed but if trying to maximize battery life, the medium and I suspect low mode are very efficient. I haven't done a run time of the low mode and probably won't bother. I estimate medium mode to be 68 lumens and low mode to be 10 lumens.

High mode - highest efficiency in the order listed from top to bottom


Medium mode

Thanks for sharing your results. Your graphs are very telling, especially with high mode. My observations when using the light are that the low and medium modes are sufficient for most times when I would use this particular light. The high is handy to have on hand for occasional use. If I think I'll need the high level for a longer period of time, I'll choose my PD22 instead.

Thanks for the graphs. I like this light for the medium and low mode efficiency and think its a great task light

Thanks for sharing... Good info and comparisons.

I estimate medium mode to be 68 lumens and low mode to be 10 lumens.

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Just a question on the 68 estimate - it looks like the D25A is running ~2900 and the E12 ~3800 or about a third higher. If I'm comfortable with ET's lumen spec of 32 lms for medium, would that mean the E12 would be ~ 43 lms (on an ET scale)?

reppans said:

Thanks for sharing... Good info and comparisons.

Just a question on the 68 estimate - it looks like the D25A is running ~2900 and the E12 ~3800 or about a third higher. If I'm comfortable with ET's lumen spec of 32 lms for medium, would that mean the E12 would be ~ 43 lms (on an ET scale)?

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You are correct that they are proportionally different from each other. The question would be which one is correct and therefore correlating the other with a proportional estimate.

I had it written down that the ET D25A XP-G2 manufacturer's spec for medium was 44 lumens but I can't verify it. If you are comfortable with the D25A being correct then that correlates to the E12 at 57 lumens. Or my estimates would put the D25A at 52 lumens and the E12 at 68.

The problem is that my data logging light meter only gives lux but what I have done to get an estimate in lumens was after taking tons of data and comparing to manufacturers specs, I came up with a constant that I multiply it by to get lumens and then compare all my lights in Excel to see how close it is. Some are above and some below. But then some times the manufacturers aren't correct either.

So it's not an exact science. Mostly what I have focused on is efficiency and comparing lights to each other.

In any case I am satisfied with the functionality of this 1 x AA torch. I would highly recommend it to anyone who asked. Thanks for the graphs! I used it today during work and tonight when I took my dog out. Still seems to be putting out full lumens. Luckily I have a 20 pack of AA's in my truck, so it will be a while before I run out! I like the flood of this light. Perhaps my testimonial is elementary, but I don't use any fancy equipment when reviewing so all I have to go on is my every day uses. So far so good!

Thanks for the runtime graphs!

According to your test the runtimes are not close to Fenix specifications. But also you estimate the brightness on mid and high to be higher. I would be interested in a runtime test of medium mode with alkaline. Do you plan to do that? According to Fenix specs alkaline provides slightly more than half the runtime than NiMh.

Thank you for the test results! What battery did you use Ni-Mh or alkalne?

I am surprised to see the LD12 doesn't seem to be performing very well on Medium compared to other lights.

hiuintahs said:

......I had it written down that the ET D25A XP-G2 manufacturer's spec for medium was 44 lumens but I can't verify it. If you are comfortable with the D25A being correct then that correlates to the E12 at 57 lumens. Or my estimates would put the D25A at 52 lumens and the E12 at 68.....

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Thanks for confirming.... I do trust ET's lumen scale (I have several D25A clickies) as it matches most of my light collection and the only reviewer on CPF that claims ANSI laboratory accuracy. The spec sheet for the D25A Mini (twisty) XP-G2 seems to list 121/32/4 as the ANSI lumens though (not sure where you got 44) so looks like 32 ET > 42 FX lumens? The 42 lumens (on my lumen scale) also feels about right based on Selfbuilt's test of the LD12.

Swedpat said:

According to your test the runtimes are not close to Fenix specifications..

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Fenix like to use 2500 mah NiMh for its specs, not sure what the OP is using.

I just compared the runtimes posted by the OP to those provided by selfbuilt for the LD10 R4 review: assuming the medium output is not much different between the LD12 XP-G R5 and the LD10 XP-G R4, I'd say the OP must have used a 2000 mAh Ni-MH for the test. The question is if with 2500 mAh LD12 XP-G R5 would have had a runtime close to the 11 hours claimed by Fenix: I find it hard to believe 500 mAh will yield a runtime 60% longer!

selfbuilt said:

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Labrador72 said:

I just compared the runtimes posted by the OP to those provided by selfbuilt for the LD10 R4 review: assuming the medium output is not much different between the LD12 XP-G R5 and the LD10 XP-G R4, I'd say the OP must have used a 2000 mAh Ni-MH for the test. The question is if with 2500 mAh LD12 XP-G R5 would have had a runtime close to the 11 hours claimed by Fenix: I find it hard to believe 500 mAh will yield a runtime 60% longer!

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Selfbuilt includes both the LD10 and LD12 on medium in the same graph and it seems the LD10 is ~ 25-30% brighter... anyways, that circuit/emitter is quite outdated and unfair to use here, I think.

Interesting point about the OP's LD12 runtime though... the OP got a full hour less than SB (6 vs 7 hrs). If I were to use the D25A "32 lm" medium mode as a benchmark (and ET uses a much more conservative lumen scale than SB) I would guess that the OPs LD12 sample is brighter on medium than SB's LD12 sample, and I'd guess by ~20%, which would offset the runtime difference (ie, about the same lumen-hours between the two).

I do agree that Fenix's 10.25 hr runtime claim... for the LD12 is quite overstated though, even with 2500 mah batts.

Labrador72 said:

Thank you for the test results! What battery did you use Ni-Mh or alkalne?
I am surprised to see the LD12 doesn't seem to be performing very well on Medium compared to other lights.

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I used 2000mAh Eneloops

The late model LD12 has issues so I used the original LD12 that first came out with an XP-G. You can search CPF for a couple of threads on the LD12. I even took the head off so that I could hook an oscilloscope to the LED to show them (Fenix) that they have issues and if fell on deaf ears..........but I digress!

reppans said:

Thanks for confirming.... I do trust ET's lumen scale (I have several D25A clickies) as it matches most of my light collection and the only reviewer on CPF that claims ANSI laboratory accuracy. The spec sheet for the D25A Mini (twisty) XP-G2 seems to list 121/32/4 as the ANSI lumens though (not sure where you got 44) so looks like 32 ET > 42 FX lumens? The 42 lumens (on my lumen scale) also feels about right based on Selfbuilt's test of the LD12.

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I don't know how I came up with it either. It might be LED lumens and not OTF lumens. My EagleTac D25A box has a sticker on it that says "Cree XP-G2, R5" so they were just using their existing inventory when they switched over to the G2 and the manual is the one for the XP-G.

At any rate it seems my lumen estimate might be a little high.......especially with the medium modes. It might not be exactly linear either because by the way I estimate it, I'm really close on the max and the lows but the middle area seems to be where I might be off.

I have a bit difficult to see the colors on my screen and the lines are thin. Is it 240 min at medium for E12?

Swedpat said:

I have a bit difficult to see the colors on my screen and the lines are thin. Is it 240 min at medium for E12?

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No, it's the violet one on top that goes to about 300 minutes. The lines look a lot better in Excel of course but by the time I do a screen shot and then scale it to the maximum allowed on CPF of 800x600 resolution, they're kind of hard to see.

hiuintahs said:

No, it's the violet one on top that goes to about 300 minutes. The lines look a lot better in Excel of course but by the time I do a screen shot and then scale it to the maximum allowed on CPF of 800x600 resolution, they're kind of hard to see.

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Ok, thanks! That's even better. Then your result isn't so much worse than the stated by Fenix. I would like to know if alkaline really provides only slightly more than half the runtime than NiMh. Do you have possibility to measure that?

Here is the comparison with an alkaline battery. I used a brand new Duracell with expiration date of 2023.

Many thanks for the effort hiuintahs! :thumbsup:

Actually alkaline performs well at medium mode. Almost 4 hours flat output. Fenix statement was 6h30m for NiMh and 3h30m for alkaline and your test shows a much less difference. Even with use of a 2700mAh NiMh the percentual difference would not be as large compared to a good alkaline as Fenix claims.

When it comes to AA-lights I use as well Eneloops and alkalines depending on the situation, and therefore I am interested in the performance with alkalines. I find the advantage with AA-lights is the possibility to use several kinds of batteries, usually at least 3, and with some lights 4, included 14500. If E12 gives almost 4 hours flat output with a Duracell, it will propably be ~3 hours even with a budget model like IKEA, because the difference is not huge between the best alkalines and some of the budget models.

Thanks again, I have now decided to get the E12. The medium mode is a good allround mode and will be most used with this light.

Even though the alkaline battery pretty much died, it seemed to have enough power to keep the light going with some light for a long time after I shut it off the test.

You will like the light. I think the tint is good. I know some folks don't like the reverse clicky switch but I think the other advantages offset it........especially the price.

thanks for taking the time to do this but the lines in the legend are too thin, and the JPEG compression destroys them which makes them unreadable

pls take screenshot again then save as higher resolution PNG

The lines are just a little thin but could tell them apart all right even on my phone!