Adding a battery need help with wiring.

biglurr54

Petty Officer 1st Class
Joined
Feb 14, 2011
Messages
234
I'm adding a 2nd battery to my bow rider. I want it to run the stereo, interior lights, running lights, and cigarette lighter. I have everything all wired to properly to the back of the boat. I would like to be able to change both batteries when the motor is running. I had a marine battery switch. It's different than what the new ones look like. It has positions for bat 1, combined, and off. I was going to wire it so I could select which battery I want to run things off but I don't think I can with this switch. On the back there are four posts. Two that say bat one and two that say bat two. Any ides how I can with this to isolate the batteries and chose which one to use? Or other ways to wire this up.
 

jmarty10

Chief Petty Officer
Joined
Aug 6, 2007
Messages
560
Re: Adding a battery need help with wiring.

There are a ton of threads on this under electronics, electric and trolling motor section. Silvertip has posted numerous explanations there. Do a search on "dual battery wiring" under that section.
 

NYBo

Admiral
Joined
Oct 23, 2008
Messages
7,107
Re: Adding a battery need help with wiring.

I think you need a different switch to do what you want.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Adding a battery need help with wiring.

You don't have a dual battery switch. You do have either an isolator or an ACR. Neither one allows you to select which battery will power stuff. I also question your statement about having everything else properly wired to the back of the boat. Just exactly what do you mean by that. Just so you know, your boat, with just the single battery, has two electrical "systems" (not circuits). The large battery cables that go to the engine are the beginning of the "engine electrical system". From the engine power is routed through the engine harness up to the controls and the helm where the instruments get their power via the ignition switch. All other accessories are NOT powered via this system. Your boat should have a pair of #8 or #10 wires (one red one black) going up front to feed the fuse panel. This is the "boat electrical system". All accessories except the instruments are powered via the fuse panel.

The ACR or isolator allows the engine to charge two batteries but it does not allow you to select which one powers stuff. BAT 1 is typically the starting battery. Bat 2 is the house or auxiliary battery. COMBINE means exactly that -- it parallels the two batteries. With an ACR the engine will always charge the starting battery first. When the ACR senses the battery is fully charged it directs charging to the auxiliary battery. If you have an isolator, that is a very simplistic box that has a connection for both batteries and a single input that receives charging current from the engine. The isolator keeps both batteries isolated from each other so what you have connected to one battery cannot cannot draw down the other. You need to determine what you have (Manufacturer and model number) for us to provide any more detail. Whatever you have will not allow you to do what you want to do. A dual battery switch is required which is the most inexpensive and most versatile system.
 

biglurr54

Petty Officer 1st Class
Joined
Feb 14, 2011
Messages
234
Re: Adding a battery need help with wiring.

I ran new #8 wires (pos and neg) from the battery to a fuse panel that I installed under the helm. I connected all the accessories to the fuse panel. It is a completely separate system from the engine wiring. The switch is a BlueSea 5511E. It is just the switch I do not have the relay. Could I wire it like ...

Positive wire from Fuse Block to Bat 1, terminal one.
Positive wire from Accessory battery to Bat 1, Terminal two.
Positive wire from Starting Battery to Bat 2, terminal one.
Engine wire harness to Starting battery.
Starting battery ground to Accessory battery ground.

Will this allow me to
1. In position Battery 1 on run all accessories off the fuse panel without drawing off the starting battery?
2. In combined, Charge both batteries while under way, use the Accessory to "Jump" the starting battery if necessary?

I bought some #4 wire from a welding supply store which is really heavy and good wire. I have used it before for high powered car audio systems and it has out preformed larger gauge top of the line power wires and is a fraction of the cost! So the wiring between the batteries will be heavy wire that will be able to carry the load.

If this wont work do I need an isolator? Or would I be better off buying a 1+2+both+off switch?

The Charging motor is a 1989 Evinrude 120 looper. Probably not the best charging system?

thanks for the help
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Adding a battery need help with wiring.

I have no idea what the back of this switch looks like or how it is configured internally. Without a diagram am I can only guess at what your plan is. What I can tell you is that you are better served by a true dual battery switch with OFF-1-BOTH-2 settings and wire it like I explained. Now you would have the versatility you are apparently trying to achieve. Remember -- everything, including the engine gets connected to the COM terminal on the switch.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Adding a battery need help with wiring.

I have no idea what the back of this switch looks like or how it is configured internally. Without a diagram am I can only guess at what your plan is..


Look at this, then you will understand what he is looking for. It's the only way to go.
Isolated systems and all will charge without messing with the battery switch every 5 minutes.

EDIT: Oops, wrong link, try this one.

http://bluesea.com/products/5511e

This one may explain the different setups better.
http://bluesea.com/files/resources/...g_battery_switching_and_charge_management.pdf
 

biglurr54

Petty Officer 1st Class
Joined
Feb 14, 2011
Messages
234
Re: Adding a battery need help with wiring.

Since i dont have the ACR i broke down and purchased the off + 1 + 2 + Combined switch. problem solved. its not as impresive as a ACR set up but it will allow me to start off either battery. The ACR will only protect the first battery from being drained by the acc. but it wont let the starter pull from the acc. battery. I'll throw the swtich I have back into the boat spair parts bin for the next project.
 
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