Dual Battery question Help please!

[bear_69cuda]

Morning Gang,

I was hoping to get verification to my thinking. I've presented this to 2 marina service departments, and a mobile marine mechanic... They think I'm on the correct path. But I was hoping some folk hear could take a peek as well. I've installed two batteries. One for ONLY starting the boat, and one for all my house functions. I now need to make sure when I move ignition/start wiring to start battery only that my diagrams attached are correct. The first attachment is my stock wiring diagram from the factory. The second attachment in my modified diagram. Please note that I have VSR and battery switch 1/1 and 2/2 and combine from blue sea systems. Bat 2 is house and bat 1 is crank. I'm running 12v+ power from starter or slave solenoid to an in-line 15A fuse for ignition switch, and diverting power 8AWG red wire 12v+ from helm fuse-box to battery 2 (house) instead of battery 1 like stock config.

PS where the two red leads cross (in front of in-line 15A fuse) , are NOT connected in any way!

Thanks for any insight!

 

[Mark42]

Re: Dual Battery question Help please!

Hey Bear!

The updated diagram looks like the two batteries and their respective circuits are isolated from each other. So the diagram is doing what you want. I'm not sure where the battery switch and the charger fall into the diagram.

- How does the battery switch connect the batteries. If they are truly separate systems, then the switch is technically not needed to make the system work, but I know you have it there for some function. I assume its to connect them together so that the alternator will charge both when under power?

- Does the charger keep the batteries isolated?

Don't loose the updated wire diagram for the boat! File it with the other documents for the boat. Sooner or later, it will come in handy!

 

[bear_69cuda]

Re: Dual Battery question Help please!

Hi Mark,

I have a switch and VSR to keep batteries isolated. Charger legs are connected directly to the batteries. I just wanted to make sure I'm splicing into the stock harness correctly to isolate ignition to crank battery only. And redirect power from stock helm fusebox to house battery. See attached diagram.

I will make a nice diagram when finished and file with boat documents.

Thanks for checking this out!!!!

 

[Mark42]

Re: Dual Battery question Help please!

I just wanted to make sure I'm splicing into the stock harness correctly to isolate ignition to crank battery only. And redirect power from stock helm fusebox to house battery.

That is the way I would do it. It should work fine.

BTW, you have a lot of expensive electronics and hardware on your boat. Make sure you get a stated value policy for what you estimate it would cost to replace. Keep photos of everything, because the insurance co's underwriters will want to see some proof of your value claim.