Update to the latest software
Make sure you have installed the latest version of iPod software. iPod Software 1.2.6 or later addresses potential battery management issues. Make sure you have installed this or a later version of iPod software.
Keep iPod at room temperature
iPod's battery works best when iPod is at room temperature, generally near 20oC, but you can use iPod anywhere between 0oC to 35oC. If you have left iPod in the cold, let it warm up to room temperature before waking it from sleep. Otherwise, a low-battery icon may appear and iPod will not wake from sleep. If after warming up, iPod does not wake from sleep, connect the power adapter, and press the Menu and Play/Pause buttons until the logo appears.
Use the Hold switch
Set the Hold switch on iPod and its remote to the Hold position whenever you are not using iPod. This will keep iPod from accidentally waking from sleep and playing songs if its buttons are pressed while in a pocket or bag.
Charging
iPod fast-charges the battery to 80 percent of capacity in an hour. However, it can take 4 hours to fully recharge the battery. Even in sleep, iPod uses a small amount of current, and the battery slowly empties. Stored at optimal storage temperature, the battery will empty in 14 to 28 days.
Pause iPod when unattended
If you leave iPod unattended, press Play/Pause to pause the song. If left playing, iPod will continue to play songs until the battery is drained--particularly if the repeat setting is set to One or All.
Backlighting
Backlighting can use a lot of battery power. If you don't need to use backlighting, turn it off.
Choose Settings > Backlight Timer > Off
Equalizer
Turning off the Equalizer will extend your battery life. If you don't wish to use the Equalizer turn it off. To turn off the Equalizer,
Choose Settings > EQ > Off
Avoid changing tracks
Avoid changing tracks by pressing the Previous/Rewind or Next/Fast-forward buttons. If you frequently change tracks by pressing the Previous or Next buttons, iPod has to turn on the hard drive to open the songs. This uses a lot of battery power.
Use compressed songs
iPod's cache works best with songs of average file sizes (less than 9 MB). If your audio files are large or uncompressed (including AIFF format), you may want to compress them, or use a different compression method, such as MP3 or AAC, when importing them into iTunes. Also, consider breaking very long songs or tracks into shorter tracks that have smaller file sizes.