I found a good quality Convoy S2+ that looked nice and should be compatible with 18350 cells. It also was within my budget.
I intentionally choose the warm white XML2 T6-4C LED because I when hiking and camping, I find the cold/neutral white a bit too "harsh" and unpleasant for reading.
I already have an "eagle eyes" branded light for 18650 cells that I quite like. Some of my cells would not fit into that light.
|The strip for the protection circuit adds a few 10ths
|The bulge is just 4mm wide
|Not too much pressure and a pair of protective pads!
And sure enough:
|The battery now fits nicely
|Ain't she a beauty?
(And: No, the battery is not the limiting factor here.)
Low: 57 mA
As opposed to my similar looking (different driver, though) Eagle Eye X2 (with a XM-L T6 U2-1A) emitter. (That I use with a 3100mAh 18650 cell.)
High: 1980mA (no wonder this thing gets hot!)
Bottom line: The combination of this LED and driver seems great for the small cell. I especially like the low light mode, which should last for about 15 hours with the 900mAh cell The XML2's improved efficiency over the older XML is very well used in this scenario.
PS: The Convoy S2+ also works great with a CR123 cell.
PPS: To change between 3 and 5 modes (incl. strobe / SOS), switch the light off briefly after it has flickered in low-power mode.