Your iPod's battery is a lithium polymer that's rated for 500 or more charging cycles. (A charging cycle is a full discharge--that is, when you run the battery all the way down until it has no charge left and follow it with a full charge.) If you recharge your iPod's battery every other day, 500 charges should last you the best part of three years (though some claim you'll get only about 18 months). If you recharge your iPod's battery less frequently, there's a good chance the battery will outlast the hard drive. Here's how to get the longest life possible.

Don't let the battery die completely
To get the most life out of your battery, don't let it discharge fully--that is, don't run it until it's dead. However little you use your iPod, recharge it fully at least once every three weeks to prevent the battery from going flat. If you go on vacation for a month, you should take your iPod with you and recharge it during that time. (But you were going to take your iPod with you on vacation anyway, weren't you?)

Reduce demands on the battery
Play your music by album or by playlist, rather than hopping from one track to another. Remember that your iPod can cache an album or playlist to minimize the time the hard disk is spinning. But when you ask your iPod to produce another track it hasn't cached, it has to spin up the hard disk and access the song.

Use AAC or MP3 files rather than WAV or AIFF (Mac users only) files. Because WAVs and AIFFs are uncompressed and, therefore, much bigger than compressed files, they prevent your iPod from using its cache effectively, so the hard disk has to work much harder.

Minimize your use of the backlight or turn it off completely. To control the backlight, go to Settings > Backlight Timer. Here, you can designate the amount of time you want the backlight to remain on (2, 5, 10, or 20 seconds), set it to Always On (not recommended, obviously, for saving your battery), or for maximum conservation, just turn it off.