My 8gb iPod Touch Battery Issues?

My iPod has lived in my car, plugged into the USB / iPod slot for about 9 months with no problem at all.

Over christmas, I unplugged it and took it on a trip with me. Upon unplugging, a problem immediately surfaced - the battery dies (on standby, not playing) in about 5 hours from a full charge.

The cable in the car isn't permanent live, so I can say with confidence that this wasn't happening before. It just started happening this one day.

Secondary to this, when plugged into the car now, when enough juice for it to play is finally attained (takes about 5 minutes from turning on the ignition), then the iPod will play around 5 to 10 tracks before all of a sudden, everything stops, the radio goes off and the "overheating" message is displayed on the iPod, though it's cool to touch...

After 60 seconds, you can press the menu button and the message is dismissed and the iPod will play another 5 to 10 tracks before the overheat message is displayed again and you have to wait another 60 seconds before it will go again....

This iPod is only about a year old. Help! Will a reset fix this? or is the battery actually dead? I don't have all of the music on this iPod on the laptop any more. Is there any way of resetting without losing everything?

Thanks,

Ben