My battery started working badly last summer - in fact I couldn't get a charge higher than 40% which only gave me about an hour charge. Well, today I did something (possibly a certain combination of putting the computer to sleep by closing the lid and unplugging and replugging at the same time) that healed the battery! It now says it's at 99% and projected time is 2.5 hours.
And believed me - in these 5 months I tried every possible trick found on Mac forums to revive my battery short of replacing the battery. I have a 3-year plan with Applecare. I couldn't get any help from Applecare (they wanted a credit card to send me a new battery - i don't have a credit card, only debit cards from my bank which they said they couldn't take!). So, it seems like my battery is healed! That's a nice thanksgiving gift!