Apple PowerBook (3400 series) - Manual (Page 90)

Maximizing work time
Your Macintosh PowerBook’s battery can provide 2–4 hours of work time
before you need to recharge. The actual work time available depends on
which model of Macintosh PowerBook you have, what equipment you’re
using with your computer, and what steps you take to conserve power while
you work.
Some battery-saving measures you can take include the following:
m Minimize backlighting of the display.
m Turn off AppleTalk if your PowerBook is not connected to a network.
m Set the hard disk to spin down after a very short interval.
m Remove PC Cards and CDs when they are not in use.
m Take advantage of the sleep and wake features of your PowerBook
whenever your work is interrupted (such as when the cell phone rings).
You just need to close the display to put the computer in sleep.
For more battery conservation tips, see the “Batteries & Power” topic area of
Mac OS Guide, available in the Guide (h) menu.
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