Solar installation

SoSound

SoSound

.
Nov 21, 2007
632
Beneteau Oceanis 34 Kingston, WA
@Grip Fast, I wired my charge controller; positive to the battery side of the house battery switch, negative to the battery side of the negative switch. I'm still in test mode with panels and charging. Once I have my additional breaker installed, I will use that breaker to turn the solar panels on or off when I want to use them. I expect to only charge my house batteries with the solar, and only when the motor and alternator are not running.

Although, having said that, I know that I ran the motor for about 20 minutes the other day to make some hot water, and I did not turn the solar charge controller off when I did it. It was late in the day, and by that time, the charge controller had gone into float mode. I hadn't thought of this scenario before, what would happen with both the alternator and the solar charger running at the same time? Would the solar controller sense the output from the alternator as a full battery and turn its output down? Or would both be pumping a lot of current into the batteries?

Here is where I admit to my ignorance, I know that I have a high output alternator, but I don't know how its output is managed or regulated...
 
Grip Fast

Grip Fast

.
Jul 1, 2020
14
Beneteau 361 Lancaster, VA
I have read so much about this that my head is spinning.
I think that I am going to default to switching solar and/or alternator off as case may be.
I do remember someone saying the regulators on either system would sort it out. Cant find it anywhere now.
 
Davidasailor26

Davidasailor26

.
May 17, 2004
5,076
Beneteau Oceanis 37 Havre de Grace
@Grip Fast this may be the thread you’re thinking of - Using solar charge controller with AC battery charger

Basically Maine says you can have all your charge sources running concurrently. It will bulk charge faster, and as the batteries get full and each charge source hits its target voltage that source will provide less current. So @SoSound you shouldn’t need to worry about keeping the solar powered off. Its controller will do what it needs to do.

Also SoSound - do you have a fuse near the batteries, or just the breaker? Do you know the Amp Interrupt Capacity (AIC) of that breaker? Fuses are usually used as primary overcurrent protection, and breakers only used further “downstream”, because breakers often can’t break the full amp output of a battery if there’s a dead short. See, for example,DC Circuit Protection - Blue Sea Systems.

Grip Fast - SoSound’s boat probably has an isolator in place to tie the banks together when being charged. I know my Beneteau of the same era does. Older Beneteaus didn’t have that I don’t think, so you might have more considerations on how to charge multiple banks with your setup.
 
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Grip Fast

Grip Fast

.
Jul 1, 2020
14
Beneteau 361 Lancaster, VA
Davidasailor26, mine just has the three switches. Positive for House, Positive for Start, Common negetive. That is how my isolation system works.

So, depending on which side of the switch the charging sources are placed, you can isolate either bank manually. What I mean is, on my boat, the shore powered charger is connected to the battery side of each switch so when both banks are on or off, the charger still charges the battery. The alternator is connected to the load side of the battery switchs so it only charges the bank that is turned on, ussually that is both when under power. But I have isolated banks to charge with the alternator. I beleive that is how the original installation of my 04 is wired.

So I am thinking the solar controller should go to the house bank, (protected by fuse) and without all the fancy ACR and other switches. I can charge the start and/or house with the alternator under power or motor sailing. When at anchor I can isolate the start, while charging the house bank with the solar. Does that make sense

I am trying to determine why I want to do anything else?
 
Davidasailor26

Davidasailor26

.
May 17, 2004
5,076
Beneteau Oceanis 37 Havre de Grace
Grip Fast said:
Davidasailor26, mine just has the three switches. Positive for House, Positive for Start, Common negetive. That is how my isolation system works.

So, depending on which side of the switch the charging sources are placed, you can isolate either bank manually. What I mean is, on my boat, the shore powered charger is connected to the battery side of each switch so when both banks are on or off, the charger still charges the battery. The alternator is connected to the load side of the battery switchs so it only charges the bank that is turned on, ussually that is both when under power. But I have isolated banks to charge with the alternator. I beleive that is how the original installation of my 04 is wired.

So I am thinking the solar controller should go to the house bank, (protected by fuse) and without all the fancy ACR and other switches. I can charge the start and/or house with the alternator under power or motor sailing. When at anchor I can isolate the start, while charging the house bank with the solar. Does that make sense

I am trying to determine why I want to do anything else?
Click to expand
Without having an ACR then yeah, connecting the solar to the house bank as you suggest is probably best. The advantage of the isolator on the newer models is that I never need to think about any of those switches or worry about forgetting to move them. House bank powers house, engine bank powers the engine, they all charge with all the charging sources, and they isolate so the engine battery doesn’t drain from house loads. But whether that’s worth the complication of the isolator is squarely in the “your boat, your choice” category.
 
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