Optimize your battery settings in Energy Saver preferences
From the Apple menu, choose System Preferences.
From the View menu, choose Energy Saver.
Click Show Details.
Choose Battery or Battery Power from the "Settings for" pop-up menu.
Choose Longest or Better Battery Life from the Optimize Energy Settings pop-up menu.
These settings will put the hard disk to sleep whenever possible and reduce the computer's microprocessor performance in order to maximize its Apple A1175 battery life. If you are using processor-intensive applications, you may wish to change these settings so the microprocessor performance is no longer reduced.
Set your screen brightness to the lowest comfortable level
Press the F1 (dimmer) and F2 (brighter) keys to dim the screen until the brightness is as low as possible and the screen is still comfortable to look at.
Turn off unused features and technologies.
Just as you would turn off the lights in an unoccupied room, turning off unused features and technologies can help maximize your battery life, too. Here are a few suggestions:
Eject CDs and DVDs you're no longer using. Every so often, the optical drive spins up to read CDs or DVDs. This consumes a small amount of power.
Disconnect peripherals when you're not using them. Connected peripherals, such as printers and digital cameras, can draw power from your Apple iBook G4 12 inch Battery even when you're not using them.
Shut down any runaway applications
If you're not in a location where you need to use AirPort or Bluetooth, you can turn them off to save power.
To turn off AirPort:
From the Apple menu, choose System Preferences.
From the View menu, choose Network.
From the Show selection, choose Network Port Configuration.
Uncheck Airport from the list.
Click Apply Now.
To turn off Bluetooth in Mac OS X 10.2 or later in :
