I've had mine for 2+ years. I power off at stops of more than 30min, it will suck the juice in sleep mode. I also keep the backlight at 0 or 20%, which is plenty to see while night riding. I haven't done an actual test, but I haven't heard the low battery warning since taking these precautions. I charge it once a week if I'm just commuting, and make sure there's a full charge if going on a long weekend ride.