sometimes you have to gamble.
After 33.5 hours at mid mode I decided it was time to move the light to see how much was left, since the battery indicator was still showing _batteries not close to discharge_. They were around 3.7 volts, so I was only halfway.
So for this light enought runtime plots.
This light?
Let's give it a name
For all you who ask the size of the head, is this the measure you wanted?