I have to say it took Apple quite a while to find this issue and that is with the first generation iPod Nano's. They were out a few years ago and now people in Japan report overheating issues, causing the iPod to melt and Apple claims this is due to the battery. They are though happy to replace it and does not require warranty. The battery is made by a third party company. The overheating issues seem to look quite bad and casing does fall apart. I wonder what took Apple so long to think about replacing it. To find out about how to replace your iPod Nano 1st gen if you live in Japan, is to give Apple support a call.