Not bad at all. Even during our taxing battery test, the machine lasted just over two hours with the GT 310M GPU enabled, and around an hour more with the integrated GPU on. This is also with Wi-Fi enabled and screen brightness locked at 65%. There's no doubt that you could push these figures for another hour or so if you lowered the brightness, disabled Wi-Fi and went easy on the multi-tasking, but for a Core i3 CPU, we're impressed. It's not the most earth-shattering figure, but it's certainly respectable given that this isn't a low-power CULV machine (nor does it bill itself as such).