Your 4G iPod's battery will eventually need to be replaced. Symptoms of poor battery performance include being unable to hold a charge and quick battery drains. Although you can take it to a certified technician at your local Apple store or mail it to Apple, you will have to pay a service and repair fee if your warranty has expired. As an alternative solution you can attempt to fix the iPod yourself by replacing the battery.
Slide the iPod's hold switch to the "ON" position by pushing it to the left. Insert the tab of the iPod opening tool between the plastic screen and metal case at the top of your iPod.
Carefully slide the tool around the edge of the device, focusing on the upper-left corner to force a small opening between the metal case and the plastic screen.
Insert a smaller iPod opening tool into the side of the iPod between the metal and plastic case, and run the larger tool around the entire iPod to release the plastic front from the metal case.
Open the iPod case but do not take off the plastic front, and turn the iPod upside down so the headphone jack is closer to you, with the dock connector at the top. Pull the orange headphone jack cable straight up to properly disconnect it.
Gently pull the white battery connector from the logic board. Unscrew the two black screws from the left side of the logic board using the Torx screwdriver.
Gently lift the hard drive, and gently pull the battery cable to lift the battery from the logic board. Insert the new battery onto the logic board, and screw the black screws back into the left side of the logic board.
Connect the white battery connector back to the logic board, and connect the orange headphone jack cable back to the logic board. Close the iPod, and gently push on the corners until you hear a snap.
- iFixit: Installing 4th Generation or Photo Battery
- "iPod & iTunes For Dummies"; Tony Bove; 2008
- Earphones on Pink image by JJAVA from Fotolia.com