Is the Quark 2xAA XML (QP2A-X) less efficient than other 2xAA XML lights?

I know Quark tends to be conservative in published runtimes, but when compared to the same Quark 2xAA light in an X-PG2 version - the XM-L again seems horribly inefficient.

What's going on? Does the flexible circuitry not work very efficiently for an XM-L?

Quark is probably my favorite brand, but - I'm really wondering about the XM-L runtimes they publish.

Check out the runtime testimonial thread, Quark AA section, there some XML runtime tests and they look pretty comparable to the XPGs.. don't forget the XML is putting out higher lumens at the same level/on the same battery.

http://www.cpfmarketplace.com/mp/sh...ght-Run-Time-Testimonials-real-world-testing!

I ran a moonlight test on LR61s (AAAA) and my XPG-S2 got twice the runtime of my XML... but my light meter rates the S2 at half the lumens of the XML - 0.17 vs 0.33. The XPG-S2 4 lms spec also metered at 2.5 lms while the XML 2.7 lm spec metered at 3 lms for me. 47s seems to getting more conservative with its specs.

I've also run random side-by-side runtime tests with my SC52 and D25A Clicky Ti, all XMLs on 1xEneloops, and found all three lights to be equally efficient +- 10% or so on a lumen-hr basis - for example at max, the SC52 metered 25% brighter throughout, but the Quark ran 20% longer. The Quark and D25A specs are highly comparable... and let's just say way more "conservative" than the SC52s ;-).

Finally check out Selfbuilt's review of the QAA2X, by far the most efficient light in the 115 lm high range, not to mention still the brightest 2AA he's tested (although the D25A2 Clicky XML would probably be right there as well).

The QAAX is still my all time favorite and after much searching, I just found a NW Pro version to match my NW Tactical version .

I went for the Quark QT2A with the XP-G2, specifically avoiding the XM-L emitter. The XM-L is too much of a monster for AA batteries and a small head. Further, let me say that the XP-G2 is entirely dazzling in this small light. So much so that there is little occasion to run at the highest available power level.
Yes, the efficiency is far greater, and you get much more lumen-minutes out of your batteries.

The trouble with published runtimes is that I could build a light that starts at 800 lumens, and steps down to 81 lumens after 3 minutes. This would give me an ANSI output of 800 lumens, and an ANSI runtime of a few hours. Amazing, right? You always should check the output charts that show relative output throughout the 'battery life' spec.

AnAppleSnail said:

...You always should check the output charts that show relative output throughout the 'battery life' spec.

Click to expand...

This is a good point, both QP2A-X and QB2A XP-G2 (same emitter/driver/specs) have been tested by Selfbuilt on Max and high - just compare the output/runtime graphs. But keep in mind that the relative output/runtime relationship is nonlinear - ie, half the relative output will result in much more than double the runtime.

FWIW, I buy XMLs in small EDC lights for the floodier beam... don't really care about the max output - moonlight, low and med are my typical LMH modes.