I have a 1985 Excella 31'er. Located behind the sofa on a shelf below the front window there is an on / off master cut off switch for the batteries. What is the rocommended use of this switch. Should I bother with it at all or is it for use when parking between trips or for long term storage. I usually remove the batteries for winter storage and keep them on a tender at home so I guess the storage issue is a non-issue.