Caliberating your iBook / PowerBook G4 batteries

I've found that over time, my iBook & Powerbook are giving false indications on the battery status, telling me it's below critical when in fact the batteries can still last a good half hour more after that.

Caliberating batteries can keep the onscreen battery time and percent display accurate.

It's time to caliberate the batteries. For iBooks and PowerBook G4s other than the PowerBook G4 (15-inch Double-Layer SD):

1. Plug the power adapter in and fully charge your computer's battery until the battery indicator lights turn off and the adapter plug light goes from amber to green, which indicates that the battery is fully charged.

2. Disconnect the power adapter and use your iBook or PowerBook. When your battery gets low, you will see the low battery warning dialog on the screen. Continue to use your computer until it goes to sleep. At that point the battery has been sufficiently drained for calibration.

3. Connect the power adapter and leave it connected until the battery is fully charged again.

Do this once, and the battery will be caliberated and you'll see the result of more accurate battery life (often resulting in longer life than before) on your next use.

Also see: Caliberating MacBook / MacBook Pro / newer Powerbook G4 batteries.