you want a motor or power "contactor"
but you could use a DC circut breaker unless it has to be automatic
NOT sure why you want to disconnect the batteries for any reason besides service or storage
don't need to disconnect converter or inverter from batteries except for those reasons, that is best done manually, less chance for slip ups
going from inverter to generator or shore power, does not require disconnecting batteries
batteries should stay connected to system at all times except service, if you use solar you want it available and charging even IF you are not there same for shore power
a transfer switch between inverter and shore cord
or just but an RV plug connected to inverter and plug in shore cord
what you want to isolate via breakers or sub panel are the outlets MW etc.. from items like water heater and converter, 120v for fridge, but you can put the fridge on LP only manually, and not worry about it