What's the longest anyone has had theirs run?
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!
EDIT: It's still going at 210 hours!!
There is a review of the light on BLF where runtime was tested at somewhere around the 160 hours mark IIRC. It's definitely my cave light! 
I remember seeing that review some time ago, but I didn't know that anyone had hit the 160 mark. Wow!
Zebralight SC600 is definitely my preferred cave flashlight, maximum runtime at 0.1 lumen is about 1920 hours (or 280h @ 2.8 lumens).
Here is a link to the review and below his power usage findings. Very impressive!
[quote=Don]
Battery Life: ★★★★★
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.
[quote]
I bought it to see how well it would perform as cave light. It's a nice light but unfortunately it's not waterproof.
good to know this. I ordered one last night.
What happened, was it the lens? Maybe put clear putty or any sealant to fix it?
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.
You’re right I tried it myself. Fixing this is now on my to do list.
Well, I'm a little surprised. My H3 is still going and it just hit the 210 hour mark!!
To ramp down to the absolute lowest setting is a chore that takes at quite a few tries. Anyone have an easy trick?
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 a noob, so please don't mind the question, but what use could the light have at its lowest setting?
Longer runtime. You’ll find out some lows are not low enough. In fact I can use a lower low for my uf-h3.
As LeeLou said longer run times. Among many uses for me during a 11 day power outage this would have been most useful as a nightlight in the bathroom.
As LeeLou said longer run times. Among many uses for me during a 11 day power outage this would have been most useful as a nightlight in the bathroom.
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.