House battery (both) not turning on --

[Reiko]

First, I am not technical and tend to take my van to a professional for issues like this. But, I'm interested in what might be the problem so -- here goes.

I have a 2018 Roadtrek SRT. When I camp I always hook up to city power. But this past weekend when I disconnected from city power, both battery indicator lights did not turn on. I drove some 4 hours and still they didn't turn on. What might be the problem?

Thanks --