I have just purchased a 85' Hunter 40. I am moving up from an 81' H30. The 40 has 6, yes 6, batteries on board. My 30 had 2 batteries. There are 3 battery switches as well. One of the former owners was an engineer, and he installed this and diagramed it as well. As I have just gottent he keys, I have not had time to go over the diagram, but I do know that I will need a book to help me understand a system this complex. Can any of you recommend a book that will explain multi battery 12 volt systems like this?Thanks!