WMOSES-Wayne does bring up some important issues even for me with the OFF-ROAD POPUP and its 5x8 front deck which catches a bunch of camping supplies and PLAN Bs items always deemed necessary to be able to make it back home in one piece.
I also have a second so called hobby associate with HAM RADIO and EMERGENCY COMMUNICATIONs which also puts my truck off road alot to operate my emergency radio OPS during bad weather etc...
I have also given some thought to this problem as well. My replacement batteries are being planned to be the TROJAN T1275s which will weigh in at 82LBs each. I have decided to split up my battery bank into two separate banks with one mounted on the trailer tongue area and the other one mounted in the Truck bed. These two locations will spread out the battery weight and give me a good 300AH battery capability in both locations that should satisfy both off-road camping with the trailer and stand alone radio comms with just the truck. The beauty of this is I can parallel the two banks when camping off the power grid and get around 600Ahs of battery capacity.
My floorplan drawings here shows this setup... The extra half of the battery box will like Wayne says be used for more setup items associated with the OFF-ROAD camping.
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The charging of the battery bank in the truck can be accomplished by this wiring scheme which will use the truck alternator or trailer on-board converter/charger when connected together. This drawing two batteries in the truck bed should show 150AH capacity on each battery - drawing needs updated.
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My OFF-ROAD POPUP and Truck weigh specs don't seem to be much of problem for me doing it this way.
Your setup is much more close to being maxed out as it is with the one battery I imagine. 1/2-ton truck for that big of a trailer is probably right at the maxed out point. Definitely something to look at before spending more monies of an updated larger and heavier battery bank.
It all takes planning for sure...
Roy Ken