4 hours on 50% screen brightness playing a stupid golf game. It's a basic game, not graphic intense. I'm kinda disappointed as well. I thought I'd at least get 7-8 hours out of it with the screen on. Now, 4 hours is still better than my MacBook Pro which would have lasted about 3 hours with the screen on continually, but I thought this was suppose to get better battery life than 4 hours with the screen on.Yes, battery life is surprisingly poor, even after the firmware update. I got about the same - 4 1/2 hours with about 40% brightness.