not asking for help - because things happen... but on our recent trip, I had two batteries in parallel, an Interstate (provenance unknown, came with the used camper) and an Everstart (2016) - one each side in the rear under-seat spaces. I checked the cells about two weeks ago - all cells full. Checked today, one cell in the Interstate was bone dry. Both had been charged (in parallel) by the Renogy Rover Controller with daily DC-DC boost (using a Renogy unit) from other exterior battery-PV setup (due to issues with forest canopy over the Aliner). I will replace both batteries and start again with a matched pair. The boiled-off acid damaged my backpack and my wife's backpack in a few places (because the vented battery box lid came ajar. My two vented battery boxes inherently have a problem - if you clamp them tight then you have a real pain to inspect the cells. I am reluctant to move the (inside) batteries outside, on to the tongue - because there not much space for two batteries and the propane tank.