Relocate batteries to reduce tongue weight

shooted wrote:

Strabo wrote:
Your towing with a '03 Ford Expedition, what did you expect? Its a Mid Class SUV.
Buy a real truck, any flavor will do. Problem solved.

I fail to understand how replacing the expedition with a "real truck" or any other tv will reduce the tongue weight of the trailer. The op did not mention a "problem", only a desire to reduce tongue weight.

Thank you, shooted.
I'm just trying to dial in the trailer for how we are going to use the trailer.
I rebuilt the battery rack under our class-C when I upgraded from a single 12v to 2-6v and it worked just fine.
I'm not expecting the towing to be noticeably improved, I'm just looking to lighten the tongue weight for the Expy.
The batteries would be more secure from tampering/theft/sun heat if caged underneath.
Running the + cable from the batteries to a master cutoff switch near the power distribution block wouldn't complicate the wiring that much. There are 3 wires connected to battery + terminal now. Moving those to the master cutoff switch will help keep them all from corroding. Yes, I will need one rather large/long cable.
I'm not sure the fire department really cares where the batteries are, but is it a good idea to have essentially an arc welder right next to the propane?
With access plates in the floor I can still easily service/check the battery's water levels. It's a good idea to check the water level regularly.
I was originally asking if anyone has seen an undercarriage mounting rack, but I think making a custom one will do. I'm also thinking of adding a second spare tire on the left side. The batteries would still fit between the spares.
When I get the trailer all loaded with our normal stuff I'll weigh the tongue. Then I'll take a second measure with the batteries sitting in the back and see what it does.