My iPod shuffle (4th gen)--lying unused for 5 years-- now won't hold charge!

…….The shuffle was bought in 2010 but I haven’t used it in all these years. I only tried to connect it recently, but while the iPod works fine and the device is recognized by iTunes and I can sync content, the battery does not seem to be holding charge.

For details:

I’ve already restored the device to the factory settings.

When the device is connected to iTunes, the amber light keeps blinking, even when it is not syncing.

Only when disconnected/ejected from iTunes, does the light goes to a solid amber. I’ve tried charging it for 8 hours at a go, but even after that the battery charge ran out after 5-7 mins of playing.

When connected to computer, even when the indicator shows a solid green and stays like that for a time, when I connect the device to iTunes, the charge indicator does not show full (it still shows the ‘lightning bolt’ symbol).

I’ve tried charging from different USB ports on my laptop (in powered mode), but with the same result.

Please let me know if this is a battery issue and if I need to get my battery replaced. Or if there is some troubleshooting I can try to solve this.

Your help is much appreciated. Thank you.