grounding house solar battery?

[blueh20]

I am running3-100w renolgy solar panels on top of my 2014 ford E250 van which go to a 40 amp renolgy commander controller then to a 255 ah lifeline batt.

Also have a Blue Sea systems charging relay ml-acr connected between house batt and starter batt with 2/0 wire pos and neg, 15' each way.
The house batt is the main batt and starter batt is aux.

Running a blue sea 100amp fuse panel(fused with 30amp breaker) for led lights, arb fridge and a flojet that pulls 7.5 amps max. All wiring is complete loops back to panel.

Question: Since the system is grounded to the frame from the starter batt should I also ground the house batt to the frame.

thanks for your input.

[BFL13]

IMO, yes. If the starter batt is out while you get a new one for instance, your house 12v things will still work if the house batt has a frame ground too.

Usually, you get alternator charging to the house batt with the engine on and that relay on the positive path closed, while the neg path is via the frame where both batts are frame grounded. In your case there is a wire for the neg path. Having that wire and the frame in parallel would reduce the R on that path and so for the circuit, and will give you more charging amps if the alternator can do any more.