Join Date: Aug 2006
Location: Arlington, VA
Thanked 14 Times in 12 Posts
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IMHO, you don't need the 8686 panel. It was designed for a two-engine system, and really complicates the install you're after, while not really adding anything valuable.
A good, robust 12V DC system for a smallish cruising boat (I assume you do have the C30 in your Profile) would consist of:
1. One house battery bank, comprised of however many house batteries you have, wired together into one large 12V bank;
2. All onboard charging sources -- alternator, battery charger, wind generator, solar panels, gas or diesel generator, etc. -- all wired directly to that house battery bank, through an appropriate CPD (circuit protection device -- fuse or breaker);
3. Assuming there's a separate starting battery, it should be maintained with an EchoCharge or DuoCharge device. For your boat, the Xantrex EchoCharge would be more than enough, and it's less costly than the Balmar DuoCharge. This device sits between the house battery bank and the starting battery, and bleeds off some charging current whenever it senses a charge on the house batteries from any source;
4. Appropriately sized cables from the batteries to the engine, alternator, distribution panel(s), etc., with appropriate CPDs; and
5. A reliable means of measuring voltage (at a minimum) or a more sophisticated battery monitoring system (like the Link series) if you wanna get fancy.
Re: battery switches, my preference would be for a simple ON-OFF switch for the engine starting battery and an ON-OFF switch for the house batteries. But, because many folks are worried about how to easily combine the batteries, you could also use a 1-2-OFF-BOTH switch, which would only combine the house and starting batteries when in the BOTH position.
If you're really worried about your kids playing with the switches, I'd find some way to put the fear of god in them to leave them alone (I had 6 kids...all grown now...who grew up sailing; NEVER had a problem with them getting near the battery switches).