Mac OS X 10.6: Battery conditions
The battery condition tells you whether your battery is functioning normally and approximately how much charge it can hold.
Here are the possible conditions:
Normal: The battery is functioning normally.
Replace Soon: The battery is functioning normally but holds less charge than it did when it was new.
Replace Now: The battery is functioning normally but holds significantly less charge than it did when it was new. You can continue to use the battery until you replace it without harming your computer.
Service Battery: The battery isn’t functioning normally, and you may or may not notice a change in its behavior or the amount of charge it holds. Have your computer checked by an Apple Authorized Service Provider (AASP). You can continue to use your battery before it’s checked without harming your computer.