Q: I want to ask how you test the battery life on your iPods, because I have a Color 4G iPod that only gets like 7 hours of playtime, but I read that you claimed to get 17 hours out of the same model. How can I acheive the battery life you do? Thanks!

- Mike

A: We have a rather detailed procedure for testing iPod battery life in our reviews, which is specifically designed to maximize the battery life. Here’s how we do it:

1. Charge iPod until full
2. Connect ear buds
3. Set volume to 50%, with equalizers off
4. Start music playing in any music category
5. Don’t touch until iPod dies!

The fifth item above is the most important, and is the primary reason that real-life iPod battery performance isn’t anywhere near Apple’s estimates. When you access the iPod’s controls to change tracks or playlists, you render the contents of the iPod’s solid-state cache (temporary, low-power memory) useless, and cause the iPod’s hard drive to spin up to fetch the music you want. This additional hard drive activity costs dearly in battery life.

However, there’s still another explanation for your less-than-optimal battery life: your iPod is simply getting old. It’s likely your iPod has seen at least a year of use - and, even if you’ve used it lightly, batteries of this type simply lose their maximum capacity with age.

To obtain the maximum battery life from your 4G color iPod, seek a replacement battery kit online, and follow our procedures above.