I bought an original iPod in 2001 or 2002 (can't remember the exact date anymore). I found it in a drawer and it still worked although the battery only lasted about 5 minutes. So I decided to refresh it. It's working great now. Here's what I did:
https://www.matthewloyal.com/moof/posts/its-alive/
https://www.matthewloyal.com/moof/posts/its-alive/