Hey Tim, to clean corrosion off an RV battery, start by turning off the engine and disconnecting the battery cables, starting with the negative terminal. Wear gloves and safety glasses. Mix a solution of baking soda and water, using about a tablespoon of baking soda per cup of water. Dip a toothbrush or small wire brush into the solution and scrub the corroded areas thoroughly. Once the corrosion is removed, rinse the battery with clean water and dry it with a clean cloth. Reconnect the battery cables, starting with the positive terminal, and make sure they are securely tightened.
Prevention is key with flooded lead-acid batteries. Regularly inspect and clean the batteries. After cleaning, apply a thin layer of commercial battery terminal protectant to the terminals to create a barrier against moisture and corrosive substances. You can also install water miser battery caps, which are designed to reduce water loss and minimize acid fumes that can lead to corrosion.
Hope this helps!