GRITDOG - My OFF-ROAD POPUP trailer stays out for some good long trips sometimes and it's Amateur Radio and COUNTY WX ALERTs not NASA haha... I can pull 20-22AMPS DC Current off my batteries for a pretty long time frame before dropping them to their 50% charge state... Then I fire up up the 2KW generator to re-charge them in a quick three hour generator run time using on-board smart mode charging.
My OFF-ROAD POPUP trailer has six-inch x two-inch A-FRAMES and it weighs in around 4200 lbs when loaded up... It was built to haul around ATV machine on the front deck so a few batteries is still less than what one of those things weighs...
Roy Ken