[rtiangha]

Stuff like that should be safe; stats are saved in the database, books to the file system. It's probably just the clock that would reset since it operates in RAM. I don't believe the clock syncs when you hook it up to a computer (but it will when connected over wifi to the internet), so it's just something that you'll need to keep an eye on and make sure to charge the battery every so often and not let it die.