Ok I seem to have the same issue with the door so I'm thinking of running #4 wire in flexible plastic conduit outside under the floor or use the existing #6 to the panel and move the converter mounted upside down to the ceiling in basement forward storage compartment and run #4 from there about 5 ft. through the floor to the fuse/battery.
I know someone will tell me my electrons will be upside down if I do that- but isn't that what the inverter is for.:-) Proton electron and neutron are at the bar drinking. Bartender says to the neutron "for you no charge."