I would think you wouldn't want to constantly be charging the battery. You'll burn up the auxilliary with a constant charge.
That's why you should have a timer on it , or some kind of disconnect. You want to get to certain voltage which is usually a little lower in a deep cycle than a cranking battery.
You also want to discharge a deep cycle battery alot more than your cranking battery.
So, get it charged up , then use it down to about 12V before recharging, it'll last longer that way.
That's what the alternator w/regulator does.......It maintains the battery at a contant state of charge..............

......... 800,000 Rv'ers can't be wrong......

Isolators allow you to discharge only the deepcycle battery and not touch the cranking battery........
