Maybe it's mainly a US thing to find 30A services... Or maybe it's that we typically camp off the beaten path... If we see an "RV Park" full of diesel pushers or multi-story 5th wheels, we keep driving.
As far as "through-hull" battery
posts, I'm not sure what you mean but there are quick connect connectors that are used for hooking up jumper cables without having to lift your hood, or other such uses. They are available in various sizes for various current ratings... Or you could get really fancy and use a Cannon or Amp mil-round connector.. I would probably not have exposed posts that a wrench could fall
on when you swap your propane
tank... I personally would never put my batteries inside in the first place. This Boler
already had a 'hole' in the floor that all the wiring to the tongue was already routed, including the battery
cables (which were only 12ga in the first place). I put a 30A breaker immediately first thing after the wires came in through the floor and made sure to adequately secure the wires along the frame to prevent abrasion.
Anyway, having said all this, the trailer referenced in this thread is now for sale
. Our recreational needs have changed...