I read a book a day, sometimes two (I'm on a ship offshore) I find the meter goes down a quarter ever 3-4 books I read. I've never let it go below half. My best guess would be about 12-16 books a charge. With my last ebook reader (a Bebook) I once left it sitting on a shelf for 3 weeks, turned on, and when I picked it up it had the same full charge I left it with. So the claims that e-ink does not use any battery except to change pages seems valid to me.