Kindle (and many other devices) use lithium polymer batteries, which don't have memory and don't require deep discharge. In fact, their life is increased when

Kindle (and many other devices) use lithium polymer batteries, which don't have memory and don't require deep discharge. In fact, their life is increased when charged often, since depth of discharge determines overall cycle count, and deep discharge on LiPo is harmful. In short, charging your Kindle frequently is just fine.