It is a good reminder that even though lithium cells are now commonplace, when things go wrong, they can go more wrong than with nicad/nimh/alkaline cells.
https://www.candlepowerforums.com/forums/smoke-and-fire-hot-cells-and-close-calls.107/
Some quick reading of links in above^, many of The vape/ E-cig devices seem like they are modified for max smoke with low resistance coils, and require cells capable of delivering 30+amps.
Seems likely cells pushed this hard, especially if not specifically designed for powering such loads, would become far more dangerous.
I am not sure the amp draw of my Armytek c2pro max on its turbo 2 setting of 3720 lumens, but I suspect less than 15 amps
I've been guesstimating at the capacity remaining in some of my 18650 cells.
The $9.19 Peetpen L21 Vikas linked, and of which I bought 3, came with 1800 mah(claimed) 18650 cells, one of which was overdischarged to 2.06v. While I have no good data on their actual capacity/ quality, yet, their heatshrink wrapping, upto the button top seems to be quality.
The cheapo headlamps I bought through Ebay, 2 for 10$, with 18650 cells soldered in place, are lasting about 2.5 hours with a 250ma draw( at 4.12v), and requiring ~700 mah to return to 4.12v from 2.91v, which I consider dim uselessness.
This small headlamp is everywhere online, in my opinion, it's a cheap headlamp worth for trying. The built-in battery(may not good one, but think about the price) can not be replaced easily, but if you can replace with a premium 18650 battery as some sofirn fans did, it becomes a long-lasting...
www.sofirnlight.com
I am considering putting my Panasonic cells in these, as the cells they come with are highly questionable. Likely rewrapped recycled laptap batteries. I had a reclaimed laptop battery phase. They were are jokes in comparison to the panasonic cells, but likely superior in capacity to the cells which came in these cheapo headlamps.
My one, many year old, Panasonic NCR18650b cell, recently, from a rested 3.69v, required 1400mah to return to 4.18v, according to my USB meter. This battery was once placed within a cheapo chinese headlamp with a dual 18650 holder that mounted on the back of the head. it came with its own charger, and that charger took this cell, and its twin, to 4.56v. This was 2014 or so. Tossed that charger.
As far as 'too bright', I do believe the 'turbo' modes, to be mostly useless as they are far too bright and heat so quickly, but I also view it like a sports car. Cant always use the power, but it is nice to have. When I get to drive a 3.8 second to 60 sports car, I feel obligated to find someplace where I can put my right foot to the floor in first, Lift, pop it into second slam right foot home, and feel the rear drift, and other places shift from first, to 5th sedately.
Almost all my regular DC powered light sources, have dimmers. I employ voltage buckers as opposed to PWM dimmers/ motor speed controllers, as the buckers do not cause whining, and will dim the LEDs far more before they shut off completely .
For workbench tasks, I found the High 550 lumen setting of my Olight H2R was often way more than needed, but the medium of 150 lumens often not quite enough. Its 1 lumen moonlight mode was not enough for comfortable reading in bed, but its 30 lumen low setting was far too much.
In this regard my Armytek C2promax warm at high @ 440 lumens should be great for workbench tasks, and had a 4.6 lumen moonlight mode which is perfect for nighttime reading in bed. The 3720 Lumen rating on Turbo 2 is ridiculous. I'll rarely ever use it, and have not yet used it for long enough for the temperature protections to kick in, but I am glad that amount of power is there, on tap, 3 clicks away.
Those cheapo lights linked above are nice, in that one can hold the button and dim them slowly, instead of a set moonlight, low, medium, high, turbo1 turbo 2 ect, even though these cheapo lights are ~ 140 lumens max.
Ideally, I'd love a high capacity IPX8 headlamp with high CRI and ~4000K color with the ability to choose flood or throw and any point in between, as well as any output level from 0.4 to 2000 lumens, and magnetic tailcap charging which I once thought of as unnecessary, is now highly desirable.
I love the 5000mah capacity of the Armytek 21700 cell, but the extra size and weight is noticeable when mounted to forehead for a while, and I prefer to use the Armytek in my Olight H2R headstrap, as it is more comfortable, although difficult to twist to aim up or down within the strap.
I am eager to see how the Sofirn hs40 performs, when it arrives, especially at a price at less than 1/3 of the Armytek c2 pro max. I think its 300 lumen medium setting should be great over the workbench, but high of 800 way too much, and turbo at 2000 lumens a nice novelty, like when I get to drive the Corvette, and find a place to safely mash the pedal and feel the raw power.