I have a kindle touch. I don't use it too often, like I leave it off for a couple of weeks because I'm busy. When I turn it back on, more than half the battery is gone, even though it was fully charged before. When it's off, I make sure it's off and I make sure the WiFi is off too, but it still happens.
См. статью: Why does my kindle touch's battery go down when it's off?