MillerMods 3-level Fenix L0P Review

[DonnyD]

I've got a duracell 30 minute charger that works on the AA and AAA type. It has a nice fan covered by a grill that blows air over the charging batts. I love it, and I have been rotating a bunch 2500mah in and out of Eric's L2P mod, like crazy, with great performance. The fan puts out, too.


Speaking of putting out, Eric really transformed the fenix L2P. I mean, face it, the L2P is calling for a mod job anyway. I like the color of the lux he used, that alone gives the light more character, and the output is fantastic. Does eric swap out the lux on the L0P mod?

And what about the charger?

 

[MillerMods]

Greg, it sounds like your cell is fully charged. I'm confused still. The runtime should be at least 2.5 to 3 times longer on high than what you're measuring. how did the test with the alkaline turn out? We'll figure this out one way or another, but something is definately wrong here. If you can, let me know what the current draw on your L0P is, that would give use a good place to start.

BTW, 4sevens is carrying my mods on www.fenixstore.com
Here's the link:
http://fenix-store.com/index.php?cPath=24

 

[greg_in_canada]

Hi Eric,

I just measured the current draw using a Sanyo 900mAh cell. The current was 1.13Amps, 0.24A and 0.12A for the 3 points on the contact ring (all measured using the 10A scale). So that gives 0.12, 0.36 and 1.13 amps for low, medium and high. The battery voltage after the test was 1.36 volts open circuit.

So it looks like it might be a combination of things: higher draw than expected, cell capacity reduction from the greater than 1C discharge rate, and perhaps my charger isn't charging them to 100%. And you said the circuit draws more as it heats up, so that would reduce the run time too.

I'm going to continue with my Alkaline run time test and I'll post an update in a while.

Congratulations on getting your mods into 4sevens store.

Greg

 

[greg_in_canada]

I added the alkaline run-time test to the second post in this thread.

It ran 25 minutes to 50%, just like the Sanyo 900mAh cell, but much less flat of course. But after the 50% point the alkaline is a better performer. The NiMh was at 25% at the 27 minute mark. The alkaline was 25% at 40 minute mark. So an extra 13 minutes of reasonably bright light.

I wish I could afford an Energizer lithium to test the light with. But I'm tapped out for a month or two.

Greg

 

[MillerMods]

I added the alkaline run-time test to the second post in this thread.

It ran 25 minutes to 50%, just like the Sanyo 900mAh cell, but much less flat of course. But after the 50% point the alkaline is a better performer. The NiMh was at 25% at the 27 minute mark. The alkaline was 25% at 40 minute mark. So an extra 13 minutes of reasonably bright light.

I wish I could afford an Energizer lithium to test the light with. But I'm tapped out for a month or two.

Greg

Well the current draw you measured helps explain it a bit. Although I thought that the one I sent you was set for stock output, so I'm wondering if I set it to a higher setting during prototyping and sent it to you on accident (You recieved only the second one that I had made at the time; perhaps I got them mixed up or something???). Also the current measurement from medium should go through both switches at the same time. The good news is, that the circuit is quite effecient, and if the current it draw is higher than stock, it will like wise produce more output than stock.
Chevrofreek will be doing runtime charts on all of my mods for 4sevens website. He will be evualuting my L0P mod with high set to drive 1.5 watts and my L1P/L2P mods. He has all of the proper equipment and know how. He will be posting runtime charts and performance comparisions. That will clear up any confusion that these results may have caused.

 

[greg_in_canada]

I agree that it's probably mostly the current draw. Without the DMM and test lead resistance the current might be close to 1.2 amps.

I put a couple of cells into my 30 minute charger overnight to see if it does trickle charging after the light turns off. The 700 mAh cell is 1.376 and the 900 mAh Sanyo is 1.409V after being out of the charger for about 8 hours. So it seems that it may be trickle charging the cells. I may do a runtime test with that Sanyo cell and see if I get another 5 or 10 minutes. That would tell us if my charger is part of the problem.

Greg

 

[greg_in_canada]

Added a photo to the first post in the thread. It shows my Arc AAA-P with clear heatshrink over the body, my L0P with heatshrink, and my Dorcy AAA.

The L0P is bigger than the Arc but I don't notice the difference in my pocket. I do notice the diameter distance when I hold it in my teeth. I'm sure I'll get used to the bigger light quickly.

You can see that the Arc has held up pretty well being carried with my coins for 1.5 years. The head is not dinged up but the knurling is worn and silvery looking. Hopefully the Fenix will hold up nearly as well as this.

Greg

 

[MillerMods]

Here's the runtime chart that Chevrofreak put together for the 1.5 watt version. The LED will flash on the low level when the battery is nearing depletion. The switcher is operating about 85% efficent on the high drive level!

This chart puts the high drive level into better perspective:

 

[greg_in_canada]

I got my L0P back from Eric. He changed the current draw on high to be the same as the stock light. I measured 750mA from a fresh charged Sanyo 900mAh cell (1.421V open circuit). The old circuit was drawing 1.13 amps (51% more).

The brightness on high is slightly reduced: EV 15.8 versus 16.1 before (81% as bright). But the run time should be much longer than the 25 minutes (to 50%) I got before.

Using a fresh charged Sanyo 900mAh cell (1.440V open circuit). The brightness was EV 15.8 at time 0. Measuring every 5 minutes it was EV 15.7 from 5 minutes to 40 minutes. At 45 minutes it measure EV15.6.

Half brightness (1 EV lower than start) occurred at 50 minutes. Quarter brightness (2 EV lower than start) occurred at 53 minutes. One eighth brightness occurred at 55 minutes.

So for a 19% reduction in brightness I got twice the run time to 50%: 50 minutes versus 25 minutes before. This is a good tradeoff for me, so I'm very happy now.

I plan to do a run-time test with an alkaline to see how much longer the 1/4 and 1/8th times are than the NiMh, since that still a very usable amount of light.

Greg

 

[geepondy]

Wow, just came across this review. Would love to see this light compared against a current gen 4 Arc AAA. Guessing by the initial numbers compared to a gen 3 Arc AAA, I'm guessing that the LOP Miller Mod on medium is still slightly brighter then a gen 4 Arc, probably less runtime but with a flatter discharge.

In the many threads in this now huge forum, has there been any posts with beamshots of the Millermod LOP in all three modes, compared to other lights, notably an Arc?