My 12VDC batteries just has a battery disconnect switch and I make sure they are fully charged then open up the battery switch. I will check them once a month and if they still read 12.6VDC I will leave them be. My trailer sits outside in CAMP BACKYARD.
They will not freeze if fully charged...
So far so good...
Another fear with 6VDC BATTERIES is you keep hearing the users telling the horror stories of now my trailer keeps blowing fuses etc and then you find out they re-connected the 6VDC batteries back up in reverse order. It is so easy to do with the same lug size terminals on the RV Batteries. Even if you had to just remove the NEGATIVE TERMINAL would be better to me than pulling one completely out. Of course different circumstances predicts different routines.
Just me thinking...
Roy Ken
