Ipod Nano does not charge in with factory interface!

[Jupiteraudi]

My old 1st generation nano would charge itself if I left it in the ipod slot/holder. So my problem is the new nano loses it's charge if it's playing or just sitting in the adaptor after several days. I could remove it every time I park or recharge it during the evenings but that is pain and rare that I remember.

Is this a setting on the ipod? Or am I missing something? I have an B7 S4 with the factory ipod interface w/ Nav and I hope some fellow Audi guys can help
me.

Thank you in advance.