Wiring solar and ACR’s

mermike · Mar 19, 2023

Wire the controller to the DC bus if you have one, or directly to the battery switch if you must. ABYC specifies no more than 4 lugs per terminal so be cognizant of that limitation and install a busbar if you will exceed it. Be sure to fuse the controller output, based on the wire size. A disconnect for the panels is also recommended.

Stu Jackson · Mar 20, 2023

fred1diver said:
what I’m not sure is how to send the power to my 2 battery system, do I just wire it to the 1-2-both switch and be done with it ?
is an ACR necessary? If so how do I wire that in my system?

It all depends on how it is wired now, and you didn't tell us.
Let's assume your alternator output goes to the C post of your 1-2-B switch, which means your switch determines both what gets charged and what battery bank(s) gets used.
Unless you want to leave your battery switch in an on position when you're away from the boat, to charge both banks automatically, you'd need something to tie them together when the switch is off.
If your solar panel is small compared to the size of the bank(s) your panel may not even have enough power to raise the system voltage high enough to trigger an ACR, which usually requires over 13 V to engage and combine.
So more info is needed, like bank size(s) and panel size.

NYSail · Mar 20, 2023

How is your alt wired? I have all charging sources going to house bank via a bus bar. Then use an arc to charge to start battery. Simple enough and don’t have to think about switching dials.
Greg

leo310 · Mar 21, 2023

What I have done is used a Victron FET to charge house and starter batteries directly I also installed a inline fuse too. You could do the same using an ARC only thing diffrent is the solar would be to the house then ARC too the starter and if I remember the only time the starter battery would get a charge is if the house was fully charged using the FET they both are charged all the time.

Maine Sail · Mar 21, 2023

This should help:

Making Sense of the ACR

DArcy · Mar 21, 2023

I set up an always on bus bar for things like the bilge pump, fridge etc. I wired the solar panel controller and battery charger here so I can shut off the main battery switch and still allow charging from all sources. I then use an ACR to combine the chargers with the starter battery (bank 2). I have the 1/2/Both switch set up so I can combine the banks if needed, for instance if the starter battery is dead. I normally operate with the switch set to 1.

DArcy · Mar 21, 2023

fred1diver said:
Hey Darcy, what are those numbers on your diagram? Wire size?

Yes, the numbers in line with the wires are gauge size. I followed this diagram when wiring the boat and it was handy to have everything in one place.

vandiver · Apr 1, 2023

Hi, maybe my schematics helps I have the same setup.

DArcy · Apr 21, 2023

fred1diver said:
I am wondering what is the purpose of the other switch between the ½/both switch and the ACR?
I like this diagram, just wondering about that switch, is it the ignition switch?

The 1/2/Both switch is to allow starting the motor from the house bank. In theory I could run the house circuits off the starting battery if I disconnect the house bank as well. I only used a 1/2/Both switch because it was already there. I would probably go with separate on/off switches if I was starting from scratch.

The other switch (on/off) is to turn off the starter battery or to isolate it in the case of starting off the house battery when the starter battery is dead. I turn it off when leaving the boat as a theft prevention, the switch is inside a locker so not easy to find.

I just realized now, it is not a good theft prevention, anyone could just switch the readily visible 1/2/Both switch to both and the motor could start

jviss · Apr 21, 2023

@DArcy wondering why you can only power your radio from the house bank. If that bank fails, it doesn't appear you can power the radio from the engine battery.

jviss · Apr 21, 2023

fred1diver said:
So the second switch is not really necessary then?

It is, to disconnect the engine starting battery in case it's dead or shorted, so you don't kill the house bank if you have to start with the house bank.

jviss · Apr 21, 2023

fred1diver said:
Ok, I will need to look into that, my system is wired so I can start from either of both at the moment

I question needing to start with both. If one bank has failed, it's best to keep it isolated from the good bank, to avoid draining it. It's also good, in an emergency, to be able to run house loads from the engine battery, presumably with the engine running.

DArcy · Apr 21, 2023

jviss said:
@DArcy wondering why you can only power your radio from the house bank. If that bank fails, it doesn't appear you can power the radio from the engine battery.

The radio in the diagram is actually the memory for the automotive stereo. The VHF is powered through the DC distribution panel just like most other DC loads. As mentioned above, I can run the house DC off the starter battery if I need to by switching to Both.

Wiring solar and ACR’s

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