I noticed that after installing 2.5.18, my battery life was severely worse than before. When installed, my battery capacity was at 80%. 9 hours later (most of which was idle), it was down to 18%, decreasing to 16% while i was watching it. However, the really freaky thing was when I connected it to a charger. It said "charging", but continued to go down! By the time I came to 14%, I felt I had no choice but to revert to 2.5.11, as I was unsure what would happen if it was completely discharged, and unable to accept charge.