Flashlight with extreme battery endurance??

I know about those fake lumen claims.
Trustfire is a notorious one 13800 Lum TrustFire 12X CREE XM-L T6 (13800 lumens)
That’s why i’m glad i found this forum to actually see the reviews including the real measurements.
That said, with tons of brand and types it would probably take me weeks to read them all.
Instead i created this thread to see if anyone know a solid flashlight that does meet my (too optimistic) requirements. :wink:

@Sidney Stratton thanks i’ll read reviews of Convoy S2+ first.

Several reasons.
A flashlight (or even 2) easily fit in the pocket of your blouse, and so it does on a front pocket of a backpack for immediate access.
A good headlamp requires more space, most likely is heavier, does up to 4 hours max on 400 lumen and is more expensive (talking about a good one, not a plastic $2,95 thing).

No, little solar panels will take forever to charge anyway so it’s a no go.

I know about these brands here but that wasn’t really the purpose of this thread.
The purpose was if anyone actually know a good one, brand including exact type that does meet (or come close to) my requirements and does have solid reviews (does not lie with their specifications etc.)
A brand that lies with their specs is for instance Black Diamond with their Icon headlamp claiming 500 lumens measured with ANSI method for 70 hours on 4 x AA batteries.

Buy 2 Wizard Pros and carry some extra batteries?

Take a look at the L shaped headlamps from zebralight, light itself is same size as a small flashlight, strap is soft elastic so compresses easily. Very light weight, available in warm white, great efficiency.

Budget L shaped headlamps also available, convoy H1, Skilhunt H03, I think jaxman make one…

I include approximate efficiency numbers in my more recent flashlight reviews. They’re not tests of driver efficiency, but the whole system based on a runtime test and estimated battery capacity.

The best I’ve seen so far is the Thrunite TC20 on its 306lm medium mode with 183 lm/W. It exceeds its advertised runtime of 10.2 hours at that level on a single 26650 battery by an hour, and output is absolutely stable until a few minutes before it shuts off.

The most efficient compact flashlight I’ve ever used is the zebralight SC700.

Maximum output of around 3,000 lumens but that only means it will be more efficient on lower modes. Probably the lightest 21700 flashlight out there. With a Samsung 50E it can put out impressive runtime.

While it is mainly current draw versus battery mah, efficiency can play a big part in run time when your talking about low lumens for hours or days.
.
Say I have a light that is drawing 100ma and we’re using a 3000mah 18650 for about 60 lumens.
3000mah / 100ma = 30 hours of runtime at 100% efficiency
If the driver is
90% efficient
30 hours x .9 = 27 hours runtime
80% efficient
30 hours x .8 = 24 hours runtime
70% efficient
30 hours x .7 = 21 hours runtime
.
The efficiency difference between some of the best and some of the worst drivers can be 6 hours or more of run time.
That’s alot when you might depend on it in a life or death situation.
You need to be looking for something that has a good useable low mode and how efficient it is in that mode.
Try to find some reviews where testing is done on the light. Zebra light is known for high efficiency drivers but they maybe others, I just dont know who they are. Reading your post #22, spend the extra and get a zebralight.

For efficiency you want a buck or boost driver, rather than linear or FET.

3000k-4000k, efficient, below $50 is hard, as most are about 5000K. Pretty much the only option is something with XHP and a boost driver like the Convoy S11 or M3 as you can select the color temperature, but their mode spacing probably is not ideal for your needs, low too low and medium too high.

If you can relax the temperature requirement I would say the Sofirn SP32A, maybe a pair of them. Its buck driver is quite efficient for its price and has a ramping mode so you can select the lowest level that you need.

If you increase your budget you have other options that were mentioned.

That 13,000 lumens is only produced for maybe 30 seconds (if you’re lucky), and then the light drops down to a much much much lower lumen level in order to avoid overheating and/or because the battery can’t deliver that much current for too long.

In other words, you get 13,000 lumen for 30 seconds, and maybe 400 lumen for the remaining 2 hours, 59 minutes, 30 seconds.

I hope you do understand how run time is measured under ANSI standard:

This means only the initial output will be 500 lumen, and then the output will begin to drop (depending on regulation), and even when it drops down to 50 lumen, they’re still counting it toward those 70 hours.

So, while there is no way you’re getting 500 lumen for the entire duration of those 70 hours on just 4 AA batteries, technically Black Diamond may not be lying. Their result may be in compliance with ANSI standard.

+1

Under $50 I think skilhunt H03/H04 or the Sofirn SP32A are one of the more pound for pound efficient ones. I also find multiple low mode options being more important than efficiency alone when trying to extend battery life. The Skilhunt’s 0.5, 5, 20 and 70 lumen modes and the SP32A’s ramping has that covered. The skilhunt has the advantage since it can double as a headlamp.

Multiple emitter Anduril lights that have a channel that can run on a single 7135 chip (e.g D4, D4v2, Fw3A, MF01 mini or maybe the new HL3A) can also be very efficient if you run them on that single 7135 channel. Usually on default (7) stepped mode they’re the first 4 modes (up to 120 or so lumens). You can set the ramping ceiling to this level and not use turbo and a MF01 mini could run a very very long time on a single 26650.

Also, consider a thrower if you need long distance lighting since they should be way more efficient for this than any super efficient floody light.

XP-L2 or SST-20 have a Vf of 2.7-2.8V at around 100lm, so a linear driver in the best case only has 75% average efficiency. If PMW is used the LED is actually run at a higher current, which it’s less efficient.

If you look at numbers, yes they don’t have the best efficiency. But in real life, I find that having the ability to adjust brightness to what is needed (especially moonlight and good low mode spacing) is much more important than just sheer % efficiency numbers when looking at runtimes.

As an example, I have a nitecore hc30 which uses a relatively efficient buck boost driver vs my modded H03 with Lexel’s FET+7+1 TA driver. If you look at numbers alone yes the nitecore is more efficient. But during camp time, for instance, I actually only need 3-20 lumens most of the time. But the HC30 only has 1 and 70 lumen mode so you end up using the 70 lumen mode all the time. For my H03 I just ramp to the minimum light I need. With the same led, 20 lumens at 70% efficiency eats way less power than 70 lumens at 90% efficiency. When going to the loo or needing light with night adjusted eyes and you only need 0.1 lumens (or even lower), you have to use 1 lumen on the nitecore. Etc, etc. So I’d argue that my skilhunt H03 is way more efficient than my hc30 for my use case.

I think the main disadvantage of having FET driven light is its very difficult to resist the urge to go Turbo for no good reason.

ANSI spex calculate runtime to the point where light output is down to I think 10% of its initial value or value at 1min operation, something like that. It’s geared towards hotwire bulbs, when that’d likely be considered “dead”. (Ie, burn off the initial voltage peak and run down ’til “dead”.)

So a 500lm light that runs ’til it’s down to 50lm is the case in question. So some mfrs of LED lights will have a drop after a few minutes, then just languish at about 11% output forever, ’til the cell can’t even maintain that, then finally drop to 10%. Call it the Volkswagen method of runtime calculation.

So no way will it sustain 500lm for 70hrs or anything close to that.

Whups, just saw Pete’s post.

Okay, so 30sec, not 1min. Close enough. :laughing:

I second that. I got really a lot of walktime from my Peak Eiger AAA - precisely because the ramping UI allowed me to adjust the output to the min. I used more at dusk and ramped down as the night set in.
I so wish there were efficient buck or boost drivers with BLF firmware available…

Also, when it comes to runtime-to-weight, 18650 with spare cells is going to win over 21700, 26650 or multi-cell lights. Though 21700 will not be much heavier and will save you some cell swaps.