dual battery

[floater212]

what is the best way to wire a dual battery setup with the 5 way switch; off - 1 on - both - 2 on - off? last year the batteries dies, had the son remove them and replace them, didn't take any pictures, it works ok but just today I installed a new trickle charger/ maintainer and found an 18" black cable (ground) laying in bottom by trim pump, not sure where it came from and where it's supposed to go? I keep both batteries on trickle charge and run them both all the time. It would be a great help if someone could show me a diagram on how it is really hooked up correct. ps. the batteries are for everything I just doubled them up so when not running motor, the stereo won't suck all the power and kill the battery. thanks, jim

 

[Chris1956]

Not sure that is called a 5 way switch.

Connect the negatives of the batteries together, and to the motor. Connect battery 1 positive to the battery switch terminal 1, and battery 2 positive to switch terminal 2.

The common terminal of the battery switch connects to the motor.

 

[floater212]

I thought that both battery negatives needed to connect together!! thanks for the info! I don't know what they call the switch either, but it has 5 positions. batt. 1 on- then off- both on- then off- batt. 2 on

 

[Earl Cordova]

Running both batteries at the same time makes sure they will both be dead at the same time.
IMO you should only run off one battery at a time.
Then when you switch over you know to charge the drained one.

 

[poconojoe]

Agree.
Don't combine both batteries under normal circumstances. Keep one for starting and one for when you're anchored and using accessories.

You only need to combine them if both are discharged and either one won't crank the engine alone.

 

[floater212]

I would have to remember to switch them so it will charge each one and back ...... what was I saying?

 

[Earl Cordova]

Not sure that is called a 5 way switch.......

Agreed.
I would call it a 5 position switch.

 

[Earl Cordova]

I would have to remember to switch them so it will charge each one and back ...... what was I saying?

It can be set up so it charges both batteries at the same time.
Mine came that way from the factory.
But will only draw power from what ever battery is switched on.

 

[floater212]

it seemed weird, two batteries, double the wires to match each one but no way to charge them both at same time unless it was on both.

 

[Earl Cordova]

it seemed weird, two batteries, double the wires to match each one but no way to charge them both at same time unless it was on both.

Not sure what you call it, since it has been over 15 years since I purchased mine.
But it is a module with two big diodes in it that allows both batteries to charge at the same time regardless of the switch position.

 

[poconojoe]

Not sure what you call it, since it has been over 15 years since I purchased mine.
But it is a module with two big diodes in it that allows both batteries to charge at the same time regardless of the switch position.

I have a Blue Sea ACR (Automatic Charging Relay).
It automatically charges whichever battery that may need it.
It's ahead of my battery selector switch, so regardless of the position of the switch, it still monitors and keeps each battery charged (as long as the engine is running).
I have two marine starting batteries.