Apple
Apple offers it’s own Battery Service for $59 plus $6.95 shipping. Apple will replace the battery for you and offers a 90-day guarantee on materials and workmanship.
iPod mini Battery (UK)
A Do-It-Yourself replacement battery kit for 1G, 2G and 3G iPods is available from iPod mini Battery with complete installation instructions for $29/£28 – a 3G iPod battery for $29/£25. We do not recommend opening the iPod using the included screw driver.
Use a thin, sturdy piece of plastic or something similar.
iPodResQ
A Do-It-Yourself replacement battery kit for 1st -4th generation iPods (with dock) and iPod mini is available from iPodResQ with complete installation instructions and tool from $24.99 to $29.99. If you’re not comfortable with opening your iPod, they offer a 24 hour mail-in service in which they will do the installation for you for $54.
Laptops for Less
A Do-It-Yourself replacement battery kit for 1G – 4G iPods and iPod mini is available from Laptops for Less with complete installation instructions for $29.
We do not recommend opening the iPod using the included screw driver. Use a thin, sturdy piece of plastic or something similar.
PDA Smart
A Do-It-Yourself replacement battery kit for 1G, 2G, 3G and 4G iPods and iPod mini is available from PDA Smart with complete installation instructions for $40 – $59 (dependent on model). If you’re not comfortable with opening your iPod, they offer a mail-in service in which they will do the installation for you for $50 – $68 (dependent on model).