www.yandina.com
Get yourself a combiner.
Wire starting battery to engine cables only.
Wires everything else to your deep cycle house battery.
Tie 2 grounds together, connect leads from combiner to both positives.
Both batterys charge when under way or when one is connected to charger.
Starting battery only drawn from when cranking engine.
Best $50 I spent.
No switch needed.
As Capt. Frank said, seen too many people leave battery to combined or both and draw them both down leaving you with NO battery.
Intestate starting and dee cycle (grp 27 or bigger if you can fit it) at $80 max each is JUST fine!
