Come on folks...Unfortunately this discussion keeps resurfacing. Charging our GD Fire's isn't rocket science--we aren't trying to launch the Space Shuttle. Engineering wisdom says recharge around mid-discharge. That could be anywhere from 35% to 65%. I wouldn't habitually wait until the discharge was at 15% though. But on the other hand there is no reason at all to be anal retentive about when to recharge. And there is no reason to hijack a thread for several pages of total off topic BS and arguing. It is your Fire, do with it what you want no matter how stupid an act that might be.