I have had my 600 for just over a month and for the first two weeks couldnt tell how much I was using as it was plugged in all the time as i was loading it up with books etc.
Since I have got my books on it I used it about 2-3 hours a day for around 10 days until it got down to 0 bars and then it said battery low but i still got about 700 page turns before it turned off so as long as it continues in that vein i will be happy
