Dimmed at the 7 hr mark but even then it could have still ran for a bit longer. It's hard to tell how much the light degrades through the voltage drop without a light meter. Not gonna spend 50+ bucks for a meter to test a light that was only $45. So next best thing for me is to check the voltage of the battery at set intervals.

I based my math off of the new Fenix TK11 using a Q5 LED at 225lumens max for 90 minutes or 12 hours @ 60 lumens. Using that info I estimate 338 lumens coming off this light. I got that number from the runtime at 60 lumens over the 12 hours, plugged in my 7 hours to figure out X is (what a single LED produced) x the cluster of 4.

X= 84.6lumens per LED x 4= 338.4 combine lumens - efficancy of the reflector which is unknown.

So Med mode is around 1/3 of total possible power output.