How quickly does this drain battery? I'm going for 10 days of hiking at Philmont this summer and was wondering if this could run for 10 days without recharging a battery. I know it seems unrealistic but i had a cheap flashlight off amazon a few years ago that lasted for about a year with one charge, probably adding up in total use time to about 30 days. Sadly this flashlight exploded while charging after the battery started to die