Improve your iPod's battery performance
[Paul Ludington] With iPods continuing to sell faster than Apple can get them to the shelves, the happy owners are interested in getting the best performance for their music listening pleasure. A few simple techniques (many of which will apply to other music players as well) will allow you to maximize your battery performance while listening to the soundtrack of your life.
Keep it at room temperature
One of the most important ways to keep your iPod battery functioning is to keep it at a moderate temperature. Cold temperatures slow down the battery's chemical reactions causing the battery to appear to be drained long before it should be. When using you iPod in cold weather, try putting it inside your coat to keep it warmer than the outside air. Hot temperatures speed up the chemical reactions causing the battery to wear-out sooner than it should. Because of this you should not leave your iPod in a hot car in the summer and only use iPod covers that allow the heat that the iPod generates to dissipate.
Use the hold switch
The hold switch can protect your iPod from inevitable button bumps that will cause your iPod to turn its backlight on or to switch songs or volume. Any button presses require the iPod to respond to the associated command which will drain the battery faster. For all models of the iPod and iPod mini hard drive based players, the hold switch is located at the top near the headphone jack. The iPod shuffle does not have a hold switch but provides a similar function by pressing the play/pause button for 3 seconds.
Pause your iPod
One of the great things about high-capacity music players is their ability to keep pumping out tunes seemingly endlessly. However, if you never stop your player you will realize that the music does in fact stop when the battery dies. Fortunately the geniuses of the world long ago invented pause buttons and Apple has graciously included them on the iPod. When you are in situations in which you are forced to stop listening to your music, press the pause button (don't forget to turn off hold first).
Turn off EQ
While using the iPod's equalizer (EQ) can provide subtle listening enhancements to your music, it also provides not-so-subtle drains on your battery. The EQ forces your iPod's processor to "think" while it changes the frequencies of the music and the thinking processor uses the battery. If you need to get more battery life and can stand listening to the default frequency output of the music you are better off turning off the equalizer altogether. One thing to keep in mind - if you set the EQ on songs in iTunes, the iPod use the setting. To get around this set your EQ to flat on the iPod which will override the per song setting. The equalizer settings can be found on the iPod's "Settings > EQ" menu.
Set the backlight timer
The backlight, while extremely useful when you are searching for songs, causes big performance hits on the battery. Apple provides several settings for the backlight and using a short timer or turning the backlight off completely will use the least power. The backlight settings can be found on the iPod's "Settings > Backlight Timer" menu.
Use small files
The iPod uses sophisticated caching techniques to play songs while using the least amount of power. and the cache works optimally with files less than 9 MB in size. This means that battery life will be best with compressed files (usually MP3 or AAC) rather than full quality AIFF or WAV files. If you can't stand the audio quality of compressed files, consider breaking your large files into smaller chunks to improve the cache performance.
Put it to sleep
Just like you, iPod's use less energy while sleeping. Although the iPod goes to sleep on its own after a few minutes of inactivity, you can speed up the process by pressing the play/pause button until the iPod turns off. To wake your iPod back up from sleeping, press any button and it will turn back on.
Keep your iPod software up-to-date
Apple continues to make improvements to the firmware that runs the iPod. Over time this has led to better battery performance for all iPods including the original iPod. The iPod software updates are included in Mac OS X's Software Update utility and as downloads on the Apple web site for both Windows and OS X users.
Use playlists or limit skipping
Skipping between tracks requires the hard drive to kick in which uses the battery. The easiest way to avoid this is to create playlists of the songs that you would like to hear ahead of time so you aren't constantly searching for your music. You can create playlists easily using iTunes on both Windows and OS X which will be copied to your iPod during synchronization. And you may even enjoy your iPod more if you listen to only the music you want to hear.