I've had my MacBoook Pro for a bit over than 11 months. Not so long ago, I remember that the battery lasted for more than three and a half hours when using the machine very lightly (some web browsing or some e-mail reading, for example), and for a bit over an hour with (very) heavy usage. But recently, I started to notice that its capacity had shortened to alarming levels: it now only lasted for about an hour with the machine idle! That didn't feel right for a machine that only had a year of life.
After installing coconutBattery, I was scared to see that the battery only had 53% of its original capacity, and that was after a modest number of 80 full charge cycles. Compared to several other similar machines with much higher cycles count and battery life, mine was in very bad condition.
I don't know if that was due to a defective battery or misuse of it (like too much heat caused by the computer damaging it), but I'm inclined to think it's the former specially because I've read similar (well, worse) problems from people that bought this same machine around the same dates.
Anyway, the thing is I went to an Apple Store on monday to explain the situation: they just took the battery, noted down the machine's serial number (no need to show the invoice!) and told me that they'd send me an SMS when they had resolved the problem. And... today... I received that message. Shiny new battery and no complaints from them! Kudos to the service, again.