Second question: I would like to add a type 27 deep cycle battery (Recieved for free)to this circuit so I have 2 batteries for camper use. I believe the differences between battery types will adverse affect total battery life so I want to keep the batteries separate in both charging and discharge circuits. What has worked for this type of application before? Simple relays to switch between? or just big switches directly in the lines with operator skill required to prevent problems. Bottom line goal it to keep the install simple and clean. Any thoughts of a circuit diagram that would accomplish this. I know just enough about electronics to be a hazard to myself (20 yr navy engineer)