Frage Ducato 8 batteries

Hi All

We have a new Columbus 641e’s with 10” uconnect screen.

The battery info on speedometer showed 3 segments lit up but during return on a long drive back from our last trip, the number of segments has now fallen to 2, rising occasionally to 3 before dropping back to 2.  I can’t find anything in the Fiat manual saying what it should be running at normally - can anyone help please?

As a separate issue, as I understand the uconnect unit has its own battery, a ‘low battery’ notification flashed up on the screen for a moment on the way home, but only the one time and very briefly.  Has anyone any clues as to why or what this might be ?

Many thanks