Hi,
If the batteries were left in place fully charged but disconnected they will not freeze.
Solar could be added, too.
fuzzdr wrote:
My Cruiser fiver came without any sort of battery switch. I plan to install a standard marine 2 place switch. I have happily used one of these in my boat since 1991. Over the winter months I remove the batteries and store them inside the heated house. Then check the electrolyte level and voltage every couple of months and top up and/or charge as required. My property is all hills and ravines which prevents my rv from any access to a 120 vac source. That means using a generator or removing the batteries and moving them to a power source.