How to use dual power source on Ursa

I came from BMPC4K where i have a temporary battery, and i'm able to switch from one battery to another without stop of recording.
After a work with a friend with his UrsaMiniPro i observed that if you finish battery during a long shot you could be off line.
Is possible to put a battery on rear plate and at same time give power to camera along XLR?
I can do that?
I fried camera?
I can choose what PowerIn are Used?
If battery stop to work camera switch immediately to other powerIN or stop to record?
i knwo could be dumb question but... to avoid to damage camera... a camera of a friend...

Carlo, The UM works like most Broadcast ENG cameras, when you have a battery mounted on the rear, yiu can plug in a second power source to the 4-pin XLR pier connection. The camera powers first from the XLR and when it drops below the minimum requirement or power is lost on the XLR it switches to the back mounted battery. The camera gives priority to the XLar source, then camera battery. You can think of the XLR source as “internal” battery on the BMCC/BMPC. Not sure if there is a way to switch power source manually, I do not think so.

When I did a lot of field interviews, we had one battery (a small 12-volt UPS lead acid battery) ready to plug into the XLR and another camera V mount battery on the back. When the V mount started getting low, we plugged the XLR in and switched out the V mount battery. The camera switches out the pier source automatically without interruption.
Cheers.

Perfect, thanks a lot, Denny you are a mine's info

Bebob.de offers hot swap adapters which power the camera without interruption for 120s:

http://bebob.de/en/v-mount/hot-swap-adapters.html

So are you Carlo and Robert too. We each have our own skills and knowledge to share.
Cheers