I’m thinking that the reason for the lack of truly “small” 18350 lights is:
If a manufacturer wants to build a small light that has minimum size and weight as a design goal, then they are incredibly likely to use the smaller and more common CR123/16340 battery format. The 18350 battery being close to the same size but slightly bigger, gets ignored.
Can you personally confirm the Sunwayman T16R takes 18350? I cannot find any documentation that says so, everything I see says 1x16340/CR123. If so, it is pretty small. Unfortunately 380Lm is not real competitive with most others in the class.
I don’t have any 18350 flashlights myself, but just curious if 16340 and 18350 cells are similar or perhaps identical? I can’t help but noticed there are several posts indicating some flashlights will take 16340 or 18350 cells?
Some 16340s are longer than the 18350, though! I received a Wuben 16340, protected, that is longer than the Aspire 18350 unprotected.
It is not larger,though!
18350 is fatter and weighs 3 grams more than 16340
18350 won’t fit my 16340 Olight S Mini:
the 18350 is not protected, it fits the PT16. A protected 18350 does not fit, too long. There is no built in low voltage protection in the PT16. I consider Protection built into the cell important if the light has no built in Low Voltage Protection and is not user monitored for Low Voltage. There is no Low Voltage indicator built into the PT16.
I recently purchased a Armytek Partner C1 V2 that was on sale for $17.00, (though shipping was $10.00), that takes both 16340 AND 18350 cells. It’s just under 3” long and a tad over 3/4” wide. It’s a neat little light.
When I compare size I also like to focus on Weight
Armytek Partner C1 specified weight empty is 57 grams
there is also a Niteye Eye 10, spec 48 grams w clip
left to right
Ti S Mini 29 grams wout clip, 32 grams w clip, PT16 does not weigh 40 grams, it actually weighs 52 grams, or 57 grams with the new pocket clip, RRT-01 actual weight is 48 grams empty, w clip
The PT-16 is 2.75” tall and 1 1/8 wide, so shorter, lighter (w out clip), but fatter, than the Armytek
The Sunwayman T16R is the same weight as the Ti S Mini, and almost as short, but fatter.