I have a 2011 MBP 13". 4GB Ram I5 Processor. After updating to Lion last year, like many, noticed reduced battery life. Went from about 8 hours of light use to 3-4 hours of light use. According to "Power" under system information my battery has 170 cycles and is "Normal". However, it seems like everyday tasks, Word, Internet, Email, ect really drain the battery down fast. Even more so if doing something like encoding a movie. (Yes I know this uses more CPU power) But should it really go from 100% to 60% for ten minutes of encoding work? Lastly, the battery only charges up to 99%. Says it is fully charged, but the red light on the MAG adapter stays red. If I press the battery indicator button on the side of the computer it still shows one flashing green light. So is it still truly charging? I guess I am trying to figure out if I need a new battery or not. I am unsure of the amount of cycles that one should get from the factory battery or the "acceptable" length of time a MBP should last on battery power with light use.