El Re-boot by itself on plugged in power... is it by design?

[gonzalexx]

I naturally apologize if this post is out of topic.
I checked the manual, and settings, but cannot find something that tells me why.
Symptom or designed behaviour?
The old 3g ipod (wheel and 4 buttons) sits on my JBL "dougnut" speaker/charger/dock.
I leave it on, running on RB, and after a while it re-boots itself, and cycles again and again.
It leads me to believe that the auto shut-off is doing it... but should it while on AC power?
Here are my specs:
iPod 3G
RB r18505-080912
(the battery is newertech 850mah... just installed yesterday - now I feel confident about shelling oysters... should be no problem)
Anyway... the battery tells me when 100% that I have 5h51m... which I find promising... when the old battery was giving up the ghost running the apple software in 20min or so... now the new one should allegedly give me 10+hours... but I am giving the benefit of the doubt to RB because it apparently does suck up juice quicker (that's another question you could help with... why? and are my settings to blame?

Anyway... I hope I gave you all you need to laugh at the newbie, and then be nice to him... me.
Thanks for your patience and attention.
(I hope I just missed something in the manual).

[Llorean]

First, the battery time estimation is not always reliable. For many players it simply hasn't been calibrated yet. Judge by doing a full test to see how long it lasts, rather than by using the estimate.

As to your dock: It may be that your dock is providing inconsistent power and somehow triggering the USB disk mode reboot.