USB devices and plug-in cards may draw power from the notebook's battery, so you should also unplug these ifpossible. Another activity that requires a lot of power is using the disc drive to watch DVDs or listen to CDs, so eject these before travelling. If you do want to listen to music, open Windows Media Player and rip the CD to the hard disk before unplugging the notebook - not only is this more energy efficient, it's more convenient, too. itself.