2 batteries for the chassis, 5 batteries for the house
Diode based battery isolator between alternator and both banks, charges everything when driving
House runs Only from the big bank
The PD70 converter and the solar charge only the big house bank
The inverters are connected to the house bank
I do have a home brew trickle battery maintainer,
That draws off the house bank to keep the chassis at low float when parked, that device IS up front under the hatch and bridges/connects between different fuse bus bars
It is a one way always on connection using a little DC to DC buck/boost converter
I can use jumper cables if I need to cross connect the two systems
There is an Emg start push button relay for self jump start
Chassis self discharge and using the button too often, is the reason for the DIY battery maintainer