Prospective House Battery Bank Siting
The only sub-floor storage that came on my Thomas 3800 is the start battery box, just aft of driver's steer wheel, and another of approximately the same size, fore of the shotgun duallies.
No clue what it was engineered to support; prolly spare fluids, tools, radiator shroud during warm weather (nippers for the driver after a rough day transporting the little nippers...)
Is there any compelling reason this oughtn't be my place to place my bank?
Those who say that it cannot be done should not interrupt the people doing it.