Be sure to charge them fully to prevent freeze. If the RV is stored where there is electricity available, a small trickle charger with float level is even better. Battery Tender Junior is about 25 bucks and does an outstanding job. Unless the batteries are together under the hood, you will need two of them.
Another popular choice is to remove both batteries and put them in your basement for the winter. This is a lot of heavy lifting. And without batteries you cannot start the engine or generator monthly for exercise and circulation.
Originally Posted by tevz32
Since winter is coming in Michigan and we won't be using our BT for a few months I have disconnected both the engine and house batteries. Good idea?