I concur with the heat challenges. We added 2X 3" blowers suppling cool air to the bottoms (intake sides) of the Multi's (4X 3kW) The original passive intakes were relocated to the top (exhaust side) of the Multi's. Even with this, we still occasionally have over-temp issues when we have guests aboard and our 4th/5th
cabin AirCons in use.
I relocated our 24V/1000AH house bank under the Master bunk (Port/Aft) This is directly behind the port
engine well firewall and provided the shortest run to cooled space. I did have to relocate the fresh
water accumulator tank a few feet forward to fit them all.