How long can the internal backup battery in my PowerBook G3 Series or PowerBook (FireWire) maintain the date and time settings?

Important: This should only be done while the PowerBook is turned off or in sleep mode.

A fully charged internal backup battery will allow you to leave a G3 Series PowerBook in sleep mode for approximately 4 minutes before it will shutdown. This should be adequate time to remove and replace a main battery.

The original PowerBook G3 Series has the ability to use two expansion bay devices and run from the AC adapter with no main battery installed.

Note: The PowerBook G3 (Bronze keyboard)and PowerBook (FireWire) do not have this capability.

If you choose to store or transport the PowerBook without a main battery installed, you should understand that a fully charged backup battery by itself will maintain date and time, as well as other PRAM (parameter RAM) settings, for approximately 5 hours after shutdown.

Storing and transporting the PowerBook with a main battery installed will greatly increase the amount of time that these settings will be maintained in nonvolatile memory.

If you find that the computer is not holding the date and time settings, first try resetting the power manager, as described in article 14449: " PowerBook: Resetting Power Manager ".

If the date and time is not held after a shutdown, it is likely that the backup battery is either discharged or needs replacement. Plug your computer ino AC power for 48 hours to fully charge the backup battery. If the behavior persists, you will need to have the backup battery replaced by an Apple Authorized Service Provider.

For additional information on testing the internal PowerBook battery, refer to article 30017: " PowerBook: Testing Backup Battery "