I turned mine on last week and messed around with it a whole bunch before dimming it to as low as I could get it, and the battery (TF Flame) was not fully charged to begin with (4.12 volts), but you know what?
It just hit the 101 hour mark a few minutes ago! ...and it seems to still be going strong.
Man, if I were going to be stuck in a cave for a few days, this would definitely be the light!
Excellent. I can get it to vary between 15 and 650mA so for a 2500mAh cell that should give about 168 hours (A week!) on lowest which I estimate to be around the same light output as the Zebralight H50 on its lowest setting. On max output of around 120 lumens, it is drawing 650mA which should give about 3 1/2hours on highest. For what I use a headlamp for 120 lumens is plenty - doing athletic things outdoors at night is not something I've done in the last couple of decades. Higher capacity cells and those with lower internal resistance may well give both better output and runtime. But I'm happy with my cheap Trustfires.
I unscrewed the tail cap, blew in battery tube and I thought I bought a whistle (I heard air hissing). After removing the switch I found out that the light has no seals but on tail. By gluing a diffuser on housing over the lens I got rid of leaking around the lens. I have to seal the switch with glue or putty.
I like the concept of this light so much that I'm seriously considering Zebralight H600.
Well, there's no easy way. It's just kind of a thing where the more you do it the better you get at nailing it on fairly low.
I must of hit mine fairly low because it just quit at 220 hours! I don't know if anyone else has gotten that long of runtime, but that's over a week long!
I’m with Leelou. I wish my UF-H3 had a lower low as well. I use mine all the time at night or when I get up in the morning so I don’t disturb my sweetie. Low could still be 1/2 or even a 1/3 of what it is and still be plenty bright to navigate the cramped bedroom and pick out clothes. I never really appreciated ultra low modes until I had a torch with one. Now I want one with 1 or less lumen.