Wiring up a dual battery switch

[rb8484]

Hey everyone.
I needed to buy a new battery for the pontoon for this season, so I figured it was a good time to upgrade to a dual battery setup, especially since I was planing on upgrading the stereo system with an amplifier.

I ordered a blue sea battery switch (off, 1, 2, both) and 2 new batteries. The switch did not come in any wiring diagrams so I started searching the web. I have seen so many diagrams, Im not sure which way to wire it up.

My main reason for this upgrade is because we anchor up for the whole day with the radio on and I dont want to be left stranded. I want to be able to have both batteries charge when I have the switch in the "both" position. Then when we anchor for the day, I want to be able to turn the switch to "2" and run off that battery when anchored. Then when we pull anchor for the day, I want to be able to turn the switch to "1" to start the engine and flip it to "both" to charge up the batteries.

I have seen so many wiring diagrams now that I have confused myself!! On the back of the switch there are 3 terminals labeled 1, 2, common.

A little help would be greatly appreciated!!!

 

[rb8484]

Re: Wiring up a dual battery switch

Is this going to accomplish what I want??

 

[rb8484]

Re: Wiring up a dual battery switch

Then I assume I hook my stereo and accessories up to battery #2?

 

[BobGinCO]

Re: Wiring up a dual battery switch

Yup.

Here's how I did the Blue Sea Add-A-Battery - it charges both batteries, and makes sure you can't drain the starting battery with the stereo.

http://forums.iboats.com/pontoons/add-battery-564233.html

 

[rb8484]

Re: Wiring up a dual battery switch

Actually, I think I have the wrong switch. It has 3 lugs on the back of the switch, so all that is doing is allowing me to charge which ever battery I want......correct?? I am just having trouble figuring it all out!!!

I assume I need a switch with 4 lugs on the back so I can isolate which battery circuit I run.

Am I making scene what I want to do?

 

[Silvertip]

Re: Wiring up a dual battery switch

Yup.

Here's how I did the Blue Sea Add-A-Battery - it charges both batteries, and makes sure you can't drain the starting battery with the stereo.

http://forums.iboats.com/pontoons/add-battery-564233.html

NOPE--You hook everything to the COM terminal on the switch INCLUDING the feed to the HELM. Wire the switch where you get the most benefit. With everything on the COM terminal you can charge either or both batteries, you can start the engine from either or both batteries, and you can operate everything on the boat from either or both batteries. I won't even get into which position to use when for the simple reason people overthink this and it is just so easy to think about your day and set the switch that serves you best for that outing. You do not need to be fiddling with the switch all the time. Where is stated that you ALWAYS start the engine on BAT #1. If BAT #1 is already charged, why discharge it when you will be using BAT #2 most of the day? Set the switch on BAT 2 and head for wherever you anchor for the day. That battery gets charged and you don't touch the switch when you arrive. There is a very good chance the engine will restart on that battery. Again you don't touch the switch and it gets charged (somewhat) on the next run. If the engine doesn't start, THEN switch to BAT #1 and back to BAT #2 after it starts. As the Kyocera copier guy says on TV -- It's just not that difficult.

 

[rb8484]

Re: Wiring up a dual battery switch

Looks like I need this switch??
Blue Seas Systems Boat Mini Battery Switch Dual Circuit Plus 6011 New | eBay

I run the stereo and lights on battery one, and hook the the engine starting to "combine both batteries"??

 

[rb8484]

Re: Wiring up a dual battery switch

So hook the wires from the helm, the stereo, lights, and starter to the COM terminal? Then hook battery 1 to terminal 1 and battery 2 to terminal 2 on the switch?

This kinda makes sense. So you will only need to switch batteries if you kill one, correct?

 

[Silvertip]

Re: Wiring up a dual battery switch

So hook the wires from the helm, the stereo, lights, and starter to the COM terminal? Then hook battery 1 to terminal 1 and battery 2 to terminal 2 on the switch?

This kinda makes sense. So you will only need to switch batteries if you kill one, correct?

Yes on the connections. No on the killing one battery. You are a traffic cop for electricity flow to and from the batteries. The battery that needs the most help is the one you select. The battery you want to protect is the one you DO NOT select. Read my post again. It explains it as simply as I can. That example was for the day you intend to sit and run the stereo all day. If you are going cruising most of the day what would you do?? Hint! It doesn't matter which battery is selected. You can charge Bat 1, Bat 2, or BOTH. Again, select the one that needs the most charge. That will almost always be battery #2 if you have a trolling motor. or high power audio system as that battery will be the most discharged. You need to remember that you will not fully recharge a deeply discharged battery in a 10 minute run back to the dock. Or a half hour run, or even an hour run. Recharge time depends on the output of the alternator on the engine. An older outboard with a 15 amp output would have to run wide open for four hours or more to replace the juice used used by an accessory that drew 15 amps over a four hour period. Some people just alternate batteries on alternate days. That keeps both batteries doing their duty.

 

[Don S]

Re: Wiring up a dual battery switch

You can use the 4 terminal switch without the ACR and it actually works better than the 1-2-Both type switches.

In the on position the start battery is hooked to the motor, and the house battery is hooked to the house systems, and they are competely isolated from each other. To charge both batteries when runnining the engine, just start the motor, then turn the switch to combine and all are being charged and the batteries are combined. Not a good idea if the house battery is real low, as it can draw down too much from the start battery. So you have to keep an eye on that. Kind of what makes the ACR handy.

 

[bthessel]

Re: Wiring up a dual battery switch

moved to its own thread.

 

[Don S]

Re: Wiring up a dual battery switch

Not to hijack his thread but I am looking to add a second battery this year to my boat. I was looking at the Blue Sea 7650 for it. What else will I need besides the switch? I have seen some say you need a bus bar, fuses, I assume I need some battery cables. Is that the correct switch to get?

That is hijacking, just start a new thread and ask your question. That's what that big red Post New Thread button is all about.