End to end on a thirty foot long run, the outside diameter of converter to battery wires should roughly be as big around as the knuckle on your index finger. Not not even a smidgen thinner.
Running new wire the length of the rig is a pain. I have had to do it professionally and did not like it at all.
The wire was pulled through lengthwise slitted 3/4" garden hose then passed forward through a frame rail. Be absolutely certain to use decent bussman breakers at both ends.
I have as an option used ARMORED 12/3 cable (wire inside a metal sheathed semi flexible outer covering) to move a converter somewhere distant. The hole in the deck must be insulated to do that.
RV manufacturers consider every penny they spend on electrical stuff (except for plastic chandeliers) to be squandering possible profit. Good luck with your project.
