3.7V Li ion Battery Replacement 330mAh for iPod Nano 2 2G 2nd Gen MP3 with Tools|Mobile Phone Batteries| - AliExpress
NEW Battery Replacement 3.7V for Apple iPod Nano 6 6th Generation Gen 616-0531 | eBay
iPod Nano 2 Battery Replacement - Repair Sharks
iPod nano (2nd Gen) Battery - iFixit
iPod Nano Battery 2G 2nd Gen Replacement 400 mAh
NEW Replacement Battery for Apple iPod Nano 2 2nd Gen MP3 2GB 4GB 8GB 200+SOLD 769173263376 | eBay
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
Old school iPod Nano battery replacement – Fix It Workshop
Replacement Rechargeable Battery for Apple iPod Nano 2 2nd Gen 2G 2GB 4GB 8GB 769173261808 | eBay