I'm kind of stuck here with this issue and wanted to see what some of you think. I have a 43 month old mid 2009 mbp that has exactly 100 cycles on its battery, and coconut battery is reporting only 72% capacity left in the battery. The energy saver control panel is reporting service battery. I took it into the apple store and they ran a hardware test on it that indicated the battery was essentially dying. If I read apple's description for unibody mbp batteries, this battery is designed to have about 80% capacity after 1000 cycles, and not after just 100. LINK I understand that over time (3 years for my mpb) the battery will lose some of its charge, but this battery is dying extremely quickly after only 100 cycles. Isn't this waaaay less than what it should be given the low number of cycles? I know people with 600 cycles and the same aged mbp who are at 91% capacity still. I do run my mbp plugged in most of the time, but I also run it off battery at least 3 times a month to make sure that the battery doesn't run down fast over time. Unfortunately, that's exactly what seems to be happening. I believe the battery is defective, but I doubt apple will agree. Do you think the battery is defective given my description above? I understand not using the battery can wear it out faster, but I make a point of giving the electrons some flow a few times each month. The only way Apple will replace batteries - a consumable - is if they are defective.