I just picked up a 2.4ghz i5 last week, and I am wondering if I have a battery problem. The computer was about 2 months old (battery had 46 cycles) when I bought it. The battery showed 93% health then. I calibrated the battery which brought it up to 95%, but I still find it is lasting more in the 5-5.5 hour range. At work I use ichat and google chrome 95% of the time, so I am not taxing this CPU at all. This is the first 15" that I have owned, so I am not sure how much the screen brightness affects battery life. On my 2009 13" pro, a few ticks of the brightness meant less than an hour of change in expected battery life. On the 15", it seems there can be 2 or 3 hours difference of expected llfe, just in a 2 or 3 ticks of the brightness. As I sit here, my battery is reading 80% full - 5:37 and I am only 3 ticks up on the brightness meter with only Chrome and iChat open. To all my fellow 15 inchers, is this normal?