You just have to make sure it's completely off after use. It has an 8-hour cutoff, but if the hologram iscrankedup, the battery will be half dead by that point. I hit the down arrow until I can't see it, and then hit it a few more times.

The factory batteries aren't very strong tobegin with, so if you get some decent replacements and turn the sight off, you should be able to get close to 200 hours on the lower settings.