Personally not really a fan of all those designs.
I only like tube lights.
If I can fit a flashlight with a bigger diameter head in my pocket, then it would make no difference if the whole light was that diameter.
Even a 26650 light can easily be gripped in one hand so the only reason to have a non-tube light is if you need a head bigger than like 40mm.
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Stuff like USB C charging, long throw / high cri / high efficiency LED options, LED and driver on same board for compactness, are all great ideas.
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Also, even though getting high numbers is cool for marketing, it’s pretty much useless for a regularly used or EDC flashlight.
Having long battery life, stable output, no drop down or FET or direct drive, is what really matters.
The longest runtime would be using a shockli 26650 5500mAh cell.
The longest runtime while minimizing mass and size is a samsung 18650 35E.
Maybe in the future 21700 cells will get better but currently the highest capacity one is the samsung 48G which is slightly worse in wh/kg and wh/L than the 18650, but it is still very close (a lot closer than the best 26650) so if you need more capacity it’s definitely the best option.
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I don’t think anything below 18650 is worthwhile even considering, having looked at the wh/kg and wh/L of the best 16340, 18650, and 14500s.