Recharging in both the computer and a recharger
You can use a single power adapter to run the PowerBook and the battery recharger at the same time.
If the PowerBook is on and contains a battery that is not fully charged, the computer charges the internal battery first. The external battery does not begin charging until the internal battery is fully charged. It takes a little over 2 hours for a fully depleted battery to charge.
If the PowerBook is in sleep or is shut down, internal and external batteries charge simultaneously. If both batteries are fully depleted, it takes about 41⁄2 hours to charge both. If the internal battery is fully charged or absent, the external battery takes a little over 2 hours to charge.
Removing or replacing the battery
mIf the power adapter is plugged in, you can use the computer indefinitely without a battery.
mIf the power adapter is not plugged in, the backup batteries in your computer protect open programs and documents for about 4 minutes, allowing you to remove the depleted battery and replace it with a charged one. (The backup batteries maintain other kinds of information, including control panel settings such as the clock time, for up to two weeks after the main battery is discharged or removed.)
To remove or replace the main battery, follow these steps:
