Battery life on the Toshiba AT300 is decent, although we didn't quite get the hours of action promised by the manufacturer.
Toshiba says that the battery will provide 10 hours of video playback, 36 hours of audio playback or 168 hours on standby. In our intensive battery test, which involves streaming and playback of HD video on a loop (of TechRadar's own Nyan creation, in case you're interested) with the brightness turned up to the max, it recorded around six hours of life.
With the brightness turned down a notch, though, and the action not so intensive, Toshiba's time estimates are much more likely.
One annoyance we did have regarding the battery is that the Toshiba AT300 doesn't charge through its Micro USB port but rather through Toshiba's proprietary port.
We know Apple, Asus and Samsung are guilty of the same crime with their devices, but it doesn't make it any less irksome. Toshiba's charger is also by far the chunkiest of the bunch, with a huge cable, so it's a hassle if you want to carry it around.