I use an FF3. Personally I don't turn mine on, until Im on a turkey. That's just me, I mean if im slipping through the woods after working a bird that didn't come in of course I leave it on, but I don't per say leave it on from the time I leave the vehicle til the time I get back. Ive never had one die on me. I keep an extra battery in my vest with a little piece of metal I use to take the cover off. I replace the battery every other season, probably wouldn't hurt to replace it every single season because they are very cheap batteries, I do know they will blink when they get low as others on here have said but ive never had mine get to that point. I hunt as much as I can in my local spring season, and typically hit a few states every year as well and ive had no issues with battery life. I have a buddy that leaves his on all day like another user said, and he has to replace his every year. He also hunts every day all day of our 6 week season....
