Wall charger working properly 30GB 5G and improperly on 80GB 5.5G

[themaiday]

Just received my second iPod, an 80GB 5.5G and rockboxed it with the latest build while full charging.
Used it some time, at 70% I plugged in the wall charger for about 2 hours. Wondering why the battery meter isn't moving, I unplugged the charger, battery meter still shows 70%. Restart, replug, nothing changed that behaviour.

It is an Artwizz 5.0Vdc 1.0A wall charger (http://www.artwizz.com/index.php?id=279&L=1).
It worked without any problems with my older 30GB 5G rockboxed iPod.

Any experiences or suggestions?

[soap]

Does the charger work in the Apple firmware?

[themaiday]

No definitly not.
I fully drained the battery to reset it, but it doesn't charge at all, not from the charger, not from USB, nothing.

[soap]

If the same problem persists in both Apple OS and Rockbox OS than the issue is hardware, and outside the scope of what we are able to provide support on.

[themaiday]

"View Battery" under Debug mode is showing slowly raising volt level of 3,392v - thats pretty low, right?
Maybe the battery is broken. That would be no problem because I receive an original battery tomorow. I hope it isn't anything else hardware related..

edit: nearly 4hours later it is 3,427v..