treebark

We have a 2015 Winnebago/Itasca Cambria. In between camping trips we store it where I can plug one electrical extension cord. Our RV has three(3) batteries. One(1) for the Engine and two(2) batteries for the house. Are the two systems isolated? If I connect an electrical two-way Y adapter, is it OK to charge the two battery systems with separate chargers, powered from the same cord? Thanks