I ran 2/0 cables to the buss bar that is connected to the shunt and the positive buss bar that then runs to the battery. I did put in a 300amp fuse in the positive cable. Those runs (which go to the wire assembly area under the trailer) were 10 feet long. I also put in a battery switch right by the inverter.
The Renogy has one hard wired outlet from which I ran 12 gauge Ancor mult-strand wire to the outlet. The inverter has 3 plug in outlets. From one of them I ran a 12 gauge extension cord to the other outlet, cutting off the female end and hard wiring it to the outlet.
That does leave me 2 more outlets on the back of the inverter if I want to plug something else in.
The battery cables went on the inside of the frame down into the area above the coroplast and then to the wire area.
The wire that ran back to the door area went down the outside of the frame, thru the black plastic thru conduit attached to the frame and then back up thru the black plastic along side of the propane line that runs to the furnace. The extension cord wire went thru the wall of the pass thru into the area under the board under the bed on to the outlet at the foot of the bed.
Hope that helps. Simple but flexible.