I have been using the same Petzel e-Light since 2007 and have yet to change the batteries. I have heard some people complain that it is not bright enough but that is not my experience. I used it on two thru hikes of the JMT with a total of about 8 hours of use and have not felt the need of anything "better" (ie, more expensive). The light uses two CR 2032 batteries and seems to go forever on one set. I carry spares in my repair kit but so far have never used them. I also carry a small pinch light (Photon) for simple, in-camp chores, for replacing e-Lite batteries in the dark and for finding gear in the tent after dark. I replace the pinch light CR 2016 batteries every spring. The e-Lite costs about $30.00.