two batteries in a cabin cruiser how to wire

2stroke1971

Petty Officer 1st Class
Joined
Nov 8, 2009
Messages
210
I bought an old Bayliner Capri, a 19 foot cabin with the Volvo powertrain.

It had no batteries in it, and Ive got a couple for it. One is a big one, and one smaller. This is the first boat Ive had that even needed a battery, except that I used one to run my fish finder and nav lights on my old skiff.

So obviously if all works the way it should, the battery charges as the boat is running. But then after a stop....I suppose it drains a bit, especially if you are running a bunch of crap like radios, videos, whatever. I think with the kids on it, I may be running a few accessories while anchored out there somewhere.

So...you obviously want enought juice in the big battery to start the motor, but I imagine you also want the second battery to charge while running.

How do you hook the two together first, so that the second battery also charges. And is there any type of switch I should rig so that when anchored for a period of time Im only using the second battery? What do some of you guys do?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: two batteries in a cabin cruiser how to wire

Use the "Search" feature. This topic is discussed to death and the answer is generally the same. Install a dual battery switch or a VSR (voltage sensing relay).
 

Seon

Petty Officer 1st Class
Joined
Apr 23, 2008
Messages
304
Re: two batteries in a cabin cruiser how to wire

...How do you hook the two together first, so that the second battery also charges. And is there any type of switch I should rig so that when anchored for a period of time Im only using the second battery? What do some of you guys do?

StandardBatterySwitchWiring.jpg
 
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