in our 33D the house batteries would not hold a charge...checking the water was such a pita that I didn't and they were dry I discovered when they were removed....I bought 4 new ones along with a remote watering system (Flow Rite was the system, but google can show you others)....about $200 for the system and they plugged right into the batteries....now I can check the water levels in all batteries in under 60 seconds....removing the upper one is the bugger....I took a 1x4 board, screwed on a flat piece of metal at an angle on the end, and put the metal on the end of the battery mount box to slide the battery out....then a fried could get the carry strap on it to lift it out....reverse procedure for putting in the new one...taped an inner tube strip on a 1/2 inch box wrench for no shorting....unplug rig from shore power, turn off all battery switches in the house, and turn the inverter off at the unit....whoever designed the battery location was not looking our for maintenance or replacement...lol