Runtimes questions - Spark, BD, ZL

I'm looking for a new headlamp - your help is appreciated. Runtime does concern me. I would like something with at least 10 hrs runtime. My main use is hiking and backpacking. Fiddling and packing and remembering to pack batteries and exrta batteries then trying to remember which ones are spent on the trail is not something I desire. I'm just absent minded enough that I would like to pack and go kind of thing - one less thing to worry about. Ideally I want "throw and go." From the specs the BD lights (Spot and Storm) seem to get a lot of runtime on 3 and 4 AAAs - 50 hours at 90 and 100 lm respectively?

Runtimes Supposedly (taken from Mfrs websites)...


Questions:
1) Does BD "TriplePower" mean at 90 lumens - it's supposed highest output?
2) Why would BD at around 90 lm get 50 hours on the same batteries as the Spark at 70 lm which 'only' gets only 5 hours?
3) Why would ZL - remarked on for it's "efficiency" - get only 2.4 hours with 2000 mAh at 63 lm when the Spark gets nearly double that at 70lm?
4) Do the BD lights get anything like their advertised runtimes at their highest settings?

Thank you.

The Zebralight is completely regulated. So it maintains a constant brightness throughout it's run time. The BD headlamps will trail off over time. That is to say that on the Storm it will start off at 100 lumens but will trail off. So when the batteries are fresh you will get 100 lumens but when the batteries are at 50% it would be putting out a lot less light.

A couple more thoughts: I'm not sure if you are aware that you are comparing specialty tints for the Zebralight and Spark to standard cool tint of the BD. The Zebralight for example has higher lumens in the cool white version.
Light Output

• High: H1 200 Lm (0.9 hrs) or H2 100 Lm (2.4 hrs) / 140 Lm (1.7 hrs) / 4Hz Strobe
• Medium: M1 30 Lm (10.5 hrs) or M2 8 Lm (26 hrs)
• Low: L1 2.5 Lm (3 days) or L2 0.2 Lm (16 days)

I'm the same and hate packing, tracking, changing, and charging batteries. I'm a camper and found these ultra efficient LEDs with low lows that last forever.... absolutely love them. Immediately made a half-dozen of my BD and Petzl headlamps and lanterns obsolete (all junk IMHO).

As d1337 mentioned BD doesn't have regulation so maybe it'll do 50 hrs on max, but it starts falling off hard before 30 mins., go to BD's own webpage for this light and click on "more tech info" they have a chart showing illumination distance on max over time:

70m - 00:00
45m - 00:30
19m - 10:00
8.3m- 30:00

I don't know Spark at all, but I have a ZL H51w. It's a great headlamp that does flashlight duty and has plenty of hands free options even without the headband. The wide selection of low lows mean you can always be as efficient as possible for a given task. They, supposedly, have a very efficient driver.

However, I'm a little down on ZL due to it having about the worst warranty in the business (my light is already a throw-away if it stops working) and I'm quite skeptical of their specs in term lumens and runtime.

I prefer FourSevens Quarks for EDC and camping and use a Quark AA X on a 14500 battery (QP2A-X w/optional 1xAA batt tube). They have best warranty and customer service in this price range. I trust their specs to be reasonably accurate and often understated, there's a huge runtime testimonial thread over in the MP forum, and using a camera light meter, have determined that my QAAX on 115 lm high, is brighter than my ZL 172 lm max.

For camping duty, I use a Nitecore top-strap headband ($11) and quite often, this wallet-able "lantern" Clicky

I like the lantern thing Reppans. :twothumbs On the lumens ratings stuff, I have found that they are usually pretty accurate according to independent tests from trusted reviewers like Selfbuilt. One thing that I have found is that floody lights can be deceiving because the light is so dispersed it doesn't "seem" as bright. I have some handheld lights with lower lumens that will light up things at a further distance because the light is more concentrated but they don't light up the periphery as much.

The Quark XML is as floody as the H51w, but anyways, I'm bouncing both lights off the ceiling and metering off a piece of paper on the floor.. that should take care the beam differences.