How Do I Charge Multiple Battery Banks With Two Alternators?

Question:

I have a two-engine boat with a "normal-sized" starter battery and a huge house bank. In my current setup one engine charges the starter battery and the other one the house bank, which is not very effective as the starter battery gets charged in just few minutes and after that it basically does nothing. How can I have both the alternators charge the big house bank after the starter battery has been fully charged? Many thanks already in advance!

Answer:

You have two choices, 1) install a battery combiner between house and engine battery, this will allow either battery bank to share a charging voltage with another bank 2) install a battery isolator on the alternator connected to the engine battery and have that battery isolator in turn charge both the engine and house battery. - Jeff