Getting Batteries and Propane Off Tongue

I made a frame for two agm batteries(mounted on thier sides) out of an old steel angle bed frame and some nuts and bolts. I mounted it between the frame rail and the skirting, bolted through the floor. Kept the oe main power feed to the tongue in place for charging from the tow vehicle and powering the tongue jack. The new cable from the battery to the power center and a dc to ac inverter is only about 2ft long. The only maintenance that I have done was to spray battery terminal protection on them when installed, and check for corrosion once or twice a year(none yet). I keep the trailer plugged in year round to keep them charged.