I have had that battery issue since the 10.2.4 updated. My battery life was around 2 to 2.5 hours before, then 50 minutes after the update. I went to the apple store and had it checked out. Mine was not under warranty. They put a store battery in and charged for a half hour. The life was almost 2 hours, only two green dots. I got the new battery and I am now letting it run down. Its in the red zone with 21 minutes left. I think getting a new battery really does fix the problem.