The battery on my 3rd generation iPod died. The iPod would only play when plugged into a power source. It was my first iPod and though I have others I wasn't ready to give it up.
I fixed it because a battery replacement looked to be an easy thing to do. I wasn't ready to throw away an otherwise a good device.
The repair was easy peasy. The hardest part is getting the case separated. It took a few tries to open the case but it was smooth sailing once that was done. Nothing to be scared of.
iFixit does a good job explaining what to do in their guides.
If you have a dead iPod laying around go ahead and take a chance on a new replacement battery. It's a relatively easy job.