Any word on the battery life on these? I'm in the market for a 7" color PDF reader (I wish Apple made a mid-size iOS device!), but all the Androids I've seen ar

Any word on the battery life on these? I'm in the market for a 7" color PDF reader (I wish Apple made a mid-size iOS device!), but all the Androids I've seen are in the 2 hour range.