iPod Nano 4. crashes instead of standby

I have a iPod Nano 4th gen.

When it stops playing and normally would turn off into a standby mode, or if I unplug it from charging or from my laptop it crashes and I have to reset (select+menu) to get it up and running again.

The biggest problem about it is that while it is crashing, it uses battery power.

This means that from a full charge to last potential time of use is only like 24 hours.

So now, in order to have it ready when I need it, it is constantly plugged in to a power source.

Battery seems fine, it's the odd crashing to is messing it up.

I have tried restoring with no succes

Any suggestions, ideas or experiences that might help?

Best

Jeppe