iLuv i601 - External battery pack + AC power adapter - Li-pol - white - for Apple iPod nano (1G) - Walmart.com
Replaced the dead battery in an old iPod Nano I bought (really wanted a cheap Product Red one) and not even 2 days later the replacement battery expanded. I would call this
Amazon.com: SWARK Battery 616-0407 Compatible with iPod Nano 5th A1320 Battery with Tools : Electronics