If you are having battery problems, this may help.

Question

This is how to calibrate the battery.
1. With the battery at a half-full charge or less, connect the device to a power source.
2. After the battery icon appears green, disconnect the device from the power source.
3. On the Home screen, select settings, and then press the center button.
4. Select general, and then press the center button.
5. Select backlight, and then press the center button to toggle through the settings until the backlight is set to always on.
6. Select brightness, and then adjust the brightness to its highest level.
7. Return to the first settings menu, and then click playback.
8. Turn energy saver off
9. Return to the main menu.
10. Select shuffle songs.
11. Make sure it starts to play the songs.
12. Set the device aside and let it play untill it turns off.
13. Once the device turns off, try to turn the device on.
Note If the device turns back on, repeat the process. Wait until it turns off again, and then try to turn it on. Repeat this step until the device no longer turns on.
12. When the device no longer turns on, connect it to a power source.
13. Fully charge the device until the battery icon appears green.
Note Remember to set backlight and brightness to their previous settings.

Answer 1

"Note If the device turns back on, repeat the process. Wait until it turns off again, and then try to turn it on. Repeat this step until the device no longer turns on. "
Sorry, this is the step I was saying is bad advice. Running the device completely down until it shuts off automatically is indeed good advice. Trying to keep powering it back on until will do so no longer is the "bad" step. This is defintely not laid out in the Apple instructions. If you keep trying to turn it off, you will put the Li-Ion into a "deep discharge" state, which has a very definite, proven negative impact on battery life. Li-Ions perform best when they are partially disacharged and recharged multiple times. Trying to run them down to "empty" (which is what the abovstep does) ruins them. In fact, any device using Li-Ions has built-in circuitry designed to prevent this from happening. That's why you're able to turn the iPod back on after you run it all the way. And that's why the circuitry tries to shut it right back off.