On my 1994 390CPMY 454’s, When underway, if I run the house battery, the house battery charges by showing 14.0 +/- volts on The starboard engine gauge at the helm. The port shows 12.7. Now if I switch over, the port shows 14.0=/- and the starboard shows 12.7. When I leave it on both to cruise then BOTH gauges show 14.0 =/- volts. Upon reaching my destination, both batteries are fully charged. is this normal or should both charge. I checked the selector switch unit her stairs and all appears not to have been mucked with. SO, what I have done is run with switch on both, and then switch to the house when I shut down engines. ??