The slower the components and the smaller the display, the less power needed to run the machine. A 12.1-inch screen uses 50 percent less juice than a 17-inch model, and getting a 4,200rpm hard drive instead of the 5,400rpm model can mean an extra 15 to 20 minutes of battery life.
Control your power
Adjust your laptop's power settings to find a comfort zone where you're using as little power as possible with no interference in your computer tasks. The path to the control panel will vary according to your operating system and setup, but for Windows XP Home and Pro users, follow these steps: Go to Start > Control Panel > Performance And Maintenance > Power Options. Set the LCD screen to go off after 5 minutes of inactivity, let the hard drive stay active for 20 minutes, and store the system's contents in RAM when it shuts down. If your laptop goes to sleep too soon, adjust the settings.
Dim all the lights
Your LCD's backlight uses up to 10 watts of power, a huge battery drain. Lower the screen's brightness to where it's comfortable to view without squinting. In addition to the Power Options settings detailed in tip 2, most laptops have convenient function keys for controlling brightness. Look for the function key with the brightness icon and a down arrow next to it. (This is the F6 key on many laptops.)
Shut down unnecessary programs
When you're running your laptop on battery power, turn off devices and programs you don't need. When not connected to a wireless hot spot, turn off the Wi-Fi hardware. If you access wireless networks with a PC Card, remove it when not connected. Listening to music via the CD-ROM drive and watching DVDs are also big battery drains.