I have a new battery that has only 3 or 4 cycles on it, that I got as a replacement a year ago. The battery and the machine it's in, a late 2008 MBP, has been sitting for the last year unused. I tried to boot it up today and it appears the battery is toast. OS X reports it as "Replace Now". I tried to charge it for a few hours but the machine shut off as soon as I unplugged it. Is there a way I resurrect this battery?
According to http://www.apple.com/batteries/notebooks.html:
If you don’t plan on using your notebook for more than six months, Apple recommends that you store the battery with a 50% charge. If you store a battery when it’s fully discharged, it could fall into a deep discharge state, which renders it incapable of holding any charge. Conversely, if you store it fully charged for an extended period of time, the battery may experience some loss of battery capacity, meaning it will have a shorter life.
So you are most probably out of luck.