On under the floor battery boxes in vehicles that customers want fancy carpet in that ends up being almost nonremovable we modify the box by cutting the triangular shaped sheet metal gusset and replace it with a frame to the outside of the box strap. This allows the battery to be slid out from underneath. Also use side post battery for obvious reason. If your wiring and charging systom are in good shape it's not too much of a burden to have to get under it every three or four years. Also, put a copper strap on the battery terminal of the alternater to give a place to hook a charger to, just in case. That's usually a 10 guage wire so it will take a 60 amp charge rate.
