[David Bott]

Welcome to the site Dick...

Not clear in your post, but where you driving for 4 hours and then stopped? I ask for if you were, your batteries should remain charged when the engine is running as the inverter batteries are changed from the engine also. Example, we drive 6 hours and stop, if I check my batteries, they are full. So if you were driving, you also may have a charging issue and that would be found in the relays.

If you were stopped for 4 hours, yes, I would suspect the batteries. We run overnight without issue.