Solar installation vs Alternator regulator

[Needtosail]

Thanks all for the info. Will make some test next spring while motoring with solar panel disconnected. If it solves the problem, might be in for the installation of a relay driven by the alternator output to disconnect the solar panel from the MPPT when the alternator is running.

That shouldn’t make any bad and I don’t really need solar when motoring with a 125 amps alternator.

If that doesn’t fix the problem, will have a look at the wiring and hardware by a pro.

Thanks all for your help.

[john61ct]

With things working properly there should be no issue at all keeping multiple independently regulated charge sources running concurrently to the same bank.

I would want to know for myself all the details of my wiring setup, get an accurate diagram drawn and track down the reason for any voltage drops measured.

That in itself would be worth hiring a pro if I couldn't do that myself.

If the problem is a too-dumb VR then it is likely the alt won't be charging a depleted deep cycle bank effectively on its own anyway.

[waterman46]

Originally Posted by Needtosail

Hello all. Newly registered but was reading the forum since a while. Very helpfull informations.

I have a solar installation with MPPT regulator. My alternator is regulated by the built-in regulator.

While motoring, the alternator can't get over 13,7 volts. I've been told that this is because at the same time, the solar MPPT regulator sends 14,3 volts to the battery. So the built-in alternator regulator reeds that 14,3 volts and then reduces his voltage to 13.7 or less to go on absorbtion or floating.

To solve that problem, i need to shut off the Solar MPPT regulator. Then, the alternator will reed the exact battery voltage ( let say 12.8 volts) and then reach the bulk charge voltage of 14,3 volts. Didn't tried it yet since boat is winterized.

Does that make sense ?
Is there a better way to solve that problem ( Balmar regulator), don't want to spend my time switching on and off the solar installation ?
Any other idea on this ?

Thanks all for your help.

From what you say, all is working fine and you have no problem, assuming those voltages are measured across the battery terminals not elsewhere. You need to understand that at any given voltage the battery will accept only one value of current at any instant, and it doesn't matter where that current came from.

If those voltages are not measured across battery terminals then do so and get back to us. Do it before thinking of making any changes.

Research the forum thread about combining multiple charge sources.

[witzgall]

If you install a Balmar external regulator, like the MC-614, you want the battery sense wire to connect DIRECTLY to most positive post of your battery bank. They typically means the post or stud where your wire feeding your house loads on the positive side is connected. Don't connect this to an isolator, to a bus bar, or anything else.

Chris

Originally Posted by Needtosail

If I install a Balmar external regulator, I know that it will sense the voltage on the output of the battery combiner. In that case, with the solar MPPT off, it would read 13,7 volts out of the combiner and then rise the voltage in order to get 14,3 volts after the combiner.(ex: 14,9 volts out of the alternator minus 0.6 volts lost in the combiner)

Am i right ?

[belizesailor]

Originally Posted by Needtosail

Thanks all for the info. Will make some test next spring while motoring with solar panel disconnected. If it solves the problem, might be in for the installation of a relay driven by the alternator output to disconnect the solar panel from the MPPT when the alternator is running.

That shouldn’t make any bad and I don’t really need solar when motoring with a 125 amps alternator.

If that doesn’t fix the problem, will have a look at the wiring and hardware by a pro.

Thanks all for your help.

As posted, if everything is working properly there is no reason to install a relay to shut off the MPPT. You really should isolate the problem.