FriendlyELEC-Forum

Looking at the 8x1.5V Battery Holder and not much info. It must do 12 volts out when plug in in the UNO Dock V2.0 but can you still plug in power so this will be like a battery backup?

-Raymond Day

From a quick look at this, there is no charging or way to have both external and battery at the same time without some kind of protection circuit. You'll need to do some additional external circuits to charge these too.