I'm running a late 2008 Macbook Pro with OS 10.6.4. The battery life is terrible. Like, in the hour and fifteen minute range on a full charge. I've tried turning everything off, wifi, bluetooth, screen brightness down and turned off the keyboard backlights. If I have no applications running, it will sometimes estimate a maximum of about two hours, but never actually give me more than about an hour and a half--if all I'm doing is surfing the net. About three months ago I replaced the internal drive with a Hitatchi 500gb drive of the same RPM as the original (5400rpm). That's the only major modification to the machine I've made and the battery life was already a problem from starters. Does it sound like there's something wrong with the battery, or is it more likely there's something else causing problems?