Parallel Batteries to Solenoid

[pangolin]

I've had this boat a few weeks now and am still figuring things out.
It is a '99 Glastron 195 sx with Volvo Penta 4.3GL SX outdrive.

This question is about the batteries. The previous owner installed a second battery along with a decent sound system. The batteries are connected through the solenoid shown in the attached picture. The main battery also has a cable that appears to connect directly to the starter. I am just trying to figure out what this all means. From what I gather a solenoid should prevent the 'main' battery from being used when the engine is off. Only the 'accessory' battery will power stereo, etc when the engine is not running. When the engine is running the alternator should charge both batteries.
Is this correct?
Also, I have a battery charger on the way, where do I hook up the charger so it chargers both? Or do I charge them separately?
For battery types, is it best for the 'battery' to be a regular starting battery and for the 'accessory' battery to be a deep cycle battery? Can they be different?

Thanks.

 

[alldodge]

The solenoid is used to combine the batteries together if the one battery will not start the motor. My formula uses the same thing, and there is a switch up by the key switch that is pressed if needed. The solenoid is an easier way to combine and is momentary where a battery switch is done manually. Here is the wiring setup for multi bank battery charger and your solenoid.

It also shows a 3-bank charger with Generator and DVSR, which can also be an ACR. The DVSR or ACR does not need to be used, just options

DVSR - Digital Voltage Sensing Relay
ACR - Automatic Charge Relay

 

[wrench 3]

If you don't have a switch to operate the solenoid, your assumption of - off with the ignition off and on with the ignition on - is probably correct.
Unless you want to switch the leads back and forth from one battery to the other you should have a two bank charger.
You can mix deep cycle and cranking batteries no problems.
That solenoid bothers me a little bit. The manufacture lists it as dust resistant not vapor proof !

 

[Silvertip]

And probably not rated for continuous operation.

 

[sam am I]

...

 

[pangolin]

Thanks all. It bothers me a bit too, I read that it is not rated for wet environments and could cause fires if it gets wet. Not good for a boat.
Are there marine type solenoids that will do the same job, reserve the starting battery for starting and the house battery for everything else when the engine is off?

 

[alldodge]

Yes there are marine rated solenoids and they "look" just like the one installed. My Formula has two of them, one for combining batteries, and one to operate the wench.



They are rated for continuous duty, but they never are turned on and left on. Google 24213-BX
The battery one should be controlled by a momentary ON, SPST

 

[JASinIL2006]

Yes there are marine rated solenoids and they "look" just like the one installed. My Formula has two of them, one for combining batteries, and one to operate the wench.

I've always wanted a power wench, but I could only afford a manual one.

:laugh::laugh::laugh:

 

[pangolin]

With the solenoid I have, how to I charge the batteries with a battery charger? I am wondering if I hook up the charger the main battery, does the solenoid allow the current to flow through thus charging both at the same time? Or will I need to charge one and then the other?
Once I hook up the charger is it easier to test with a multi-meter what is happening?
Thanks

 

[bruceb58]

Just so you know DVSR is just another name or ACR. They both combine when battery voltage gets up above a certain level.

For the solenoid you have, you need to figure out what engages it. My guess is that it only engages with the ignition on.

Do you currently have a battery switch or switches?

 

[alldodge]

I see your mixing some issues. The solenoid currently installed is to combine batteries if and when it is needed to use both batteries to start the motor.

If you install a 2-bank charger, it will charge both batteries and keep them isolated incase one has a problem.

If you want an automatic charging relay so the motor will charge both batteries when the motor is running, then install an ACR

 

[pangolin]

There are no battery switches that I know of. By the way the type of charging I am talking about it at home plugged in to an automatic battery charger.
I plan to plug attach it to the main battery and start charge and then observe what happens with the voltages in both batteries. Once plugged in is there a way to test if current is going to the second battery?

 

[bruceb58]

You can just check the voltage of the two batteries when the charger is on one.

Why not figure out what controls when the solenoid is energized? Trace back the wire from the terminal that controls it.

Just so you know, that solenoid better not be energized when the engine is not running and I doubt it is. It would drain your battery.

 

[pangolin]

Thanks. I'm going to trace the wires this weekend and see if I can figure it out. I'll let you know what I find.

 

[pangolin]

The yellow wire runs from the solenoid to a post on the ignition switch. So I think that means the solenoid only opens up when the key is turned. That should work to protect my starting battery. All the accessories function with key off or on. The red wire runs from the solenoid to a fuse panel under the dash. The red wire is on the same post on the solenoid as the house battery.

 

[alldodge]

Then it combines the batteries when the key is turned to ON and during the start cycle. If you ever have a problem with one of the batteries it will pull on the other while running.

 

[bruceb58]

I would ditch that solenoid and put in a BlueSea ACR.
https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A

 

[alldodge]

I have to agree in part.

I would install the ACR, then disconnect the feed coming from the ignition switch and give it its own Momentary Normally Open switch. The ACR will protect the batteries and charge both while the motor is running. Then the solenoid can be used to combine the batteries if needed to start the motor.

 

[bruceb58]

I would also put in a battery switch. You can use that to combine the batteries if need be to start the motor. You should always have a battery switch.

Use one of these switches. It's different than a 1/2/both switch as it has two outputs. It will connect the one battery to your sound system and the starter battery to your engine. You can also combine if necessary.
https://www.bluesea.com/products/551...Battery_Switch

I use one of these on my pontoon boat where I have a totally separate house circuit.

In combined mode:

 

[pangolin]

Yeah, that looks like a nice upgrade. I have one in my wish list on Amazon.