Maybe this would work that I found on the inet someplace:
You can calibrate your iBook, PowerBook, MacBook, MacBook Air, or MacBook Pro computers lithium ion battery for best performance.
The battery has an internal microprocessor that provides an estimate of the amount of energy in the battery as it charges and discharges. The battery needs to be recalibrated from time to time to keep the onscreen battery time and per- cent display accurate. With all iBooks and PowerBook G4 computers, except the aluminum PowerBook G4 (15-inch Double-Layer SD), you should perform this proce- dure when you first use your computer and then every few months thereafter.
PowerBook G4 (15-inch Double-Layer SD), MacBook (all models), MacBook Pro (all models), MacBook Pro (17-inch) (all models) and MacBook Air
The battery calibration for the PowerBook G4 (15-inch Double-Layer SD) and any model of MacBook or MacBook Pro has been updated because of a new battery re- leased with this computer. With these computers, follow these steps to cali- brate your battery:
1. Plug in the power adapter and fully charge your PowerBooks battery until the light ring or LED on the power adapter plug changes to green and the onscreen me- ter in the menu bar indicates that the battery is fully charged.
2. Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.
3. Disconnect the power adapter with the computer still on and start running the computer off battery power. You may use your computer during this time. When your bat- tery gets low, you will see the low battery warning dia- log on the screen.
4. Continue to keep your computer on until it goes to sleep. Save all your work and close all applications when the battery gets very low, before the computer goes to sleep.
5. Turn off the computer or allow it to sleep for five hours or more. 6. Connect the power adapter and leave it connected un- til the battery is fully charged again.
Tip: When the battery reaches empty, the computer is forced into sleep mode. The battery actually keeps back a reserve beyond empty, to maintain the com- puter in sleep for a period of time. Once the battery is truly exhausted, the computer is forced to shut down. At this point, with the safe sleep function introduced in the PowerBook G4 (15-inch Double-Layer SD) computers, the comput- ers memory contents have been saved to the hard drive. When power is restored, the computer returns itself to its pre-sleep state using the safe sleep image on the hard drive.
