"House" Wiring Question -- Installing 2nd Battery

[John Orr]

I am in the process of installing a second battery, battery switch, isolator, etc. I have a pretty good handle on the set up so far, but have questions on establishing the "house" battery side. Currently the entire boat runs off the one main battery. Like most boats, mine (Bryant 236 with a 2003 5.7l Volvo engine) basically has two major electrical groups. One circuit group deals with the engine's electrical system (starting, fuel injection, monitoring, etc). The second grouping runs of the in dash fuse panel for all accessories, lights, etc. Where is best place to break the electrical system in half? Seems to make sense the entire engine system would be on one battery and the accessories on the other. Any suggestions? If my logic is so far correct, where is the proper location to actually break off the accessory wiring from the existing battery? Thanks in advance.