Alternator advice needed

[Bmarler]

i'm not sure why you think you need an isolator in the first place. if all you have is a starting bank and a house bank charged with a dc/dc charger, why bother?
take the alternator direct to the starting bank and let the dc charger do it's thing charging the house bank. the dc charger should have diode protection to prevent current flowing the wrong direction. some sort of manual switch to isolate the house bank is probably a good idea, but an isolator seems unnecessary unless the dc charger specifically requires it. if that were the case an acr might be a better choice.

 

[CMS]

Two 30A Victron controllers charging my lithium house bank. Once the isolator decides to send current to this bank, the dcdc controllers are doing their job and charging the lithiums just fine. I can see that on my phone.
He original idea with the isolator was to charge the starting batteries first, and fill up the lithiums afterwards, while underway.

What would an ACR do for me?

the ProIso does not really do that it is just a marketing gimmick...

Alt directly to Start Batt. Start batt directly to DC to DC, done...

 

[LeoKa]

https://www.victronenergy.com/battery-isolators-and-combiners/argo-fet-battery-isolators

I was thinking about getting one of these. What do you think?
My dctodc chargers are Victron, too.

I have placed an order for this Victron isolator. 200A for two banks. Once I installed it, I’ll report back of the results.
I am kind of tired of the ProMarine troubleshooting.
My original issue was to determine any problems with the alternator. That is a bigger job to replace and more expensive. It seems that the alternator is working now. Let’s see what happens with the Victron?

I could just connect the alternator directly to the crank batteries and charge my lithiums with the solar farm I am building up in the future. This might still happen, but with diesel pricing over $6 I do not sail far lately. The isolator solution was an idea for immediate charging to both banks, regardless of the trips length.

 

[Bmarler]

I have placed an order for this Victron isolator. 200A for two banks. Once I installed it, I’ll report back of the results.
I am kind of tired of the ProMarine troubleshooting.
My original issue was to determine any problems with the alternator. That is a bigger job to replace and more expensive. It seems that the alternator is working now. Let’s see what happens with the Victron?

I could just connect the alternator directly to the crank batteries and charge my lithiums with the solar farm I am building up in the future. This might still happen, but with diesel pricing over $6 I do not sail far lately. The isolator solution was an idea for immediate charging to both banks, regardless of the trips length.

this only makes sense if you're charging the lithiums directly from the alternator. i think that we all thought you had a dc-dc charger for the lithium bank.
if in fact you have a dc-dc charger for the lithiums, you don't need any isolator at all unless your charger specifically requires it.
with the power that lithiums can absorb, charging direct from the alternator is probably not a good thing. without good regulation and temp sensors on the alternator you can ruin it pretty easily.

 

[LeoKa]

I don’t have to charge the lithiums from the alternator necessarily. As I said, a solar panel setup will do that in the future. It was just an idea to connect the dctodc chargers to a free battery bank connection on the isolator. The dctodc chargers can take broad range voltages and they are protected by breakers. My lithiums can provide to the house needs for 3-4 days strait without charge. I’ve tested this already. So I am not really concerned about the lithium charging.

My main interest is to charge the cranking batteries all the time. Underway, on generator, on shorepower, etc. An isolator included will make my life easier and my lithiums could get charged, too. As long the isolator is working properly. Let see what the Victron isolator will do for my needs.

 

[LeoKa]

Hopefully the final conclusion has arrived. It was the ProMarine isolator. It is faulty.
The new Victron isolator has arrived, installed, and functioning. It does what I wanted the isolator to do. Sends voltage to the starting batteries 14.2V and the dctodc chargers. I set the dctodc units to lithium configuration and the incoming 14.2V is sent out as 13.8V charging voltage to the bus bar where the lithiums are connected. This happens at any rpm on the main engine.
I have measured the voltage with a digital meter at the alternator, at the isolator terminals, at the batteries. Pretty much 14.2V everywhere.
Also, my voltmeter shows proper voltage in the PH. Same as it was with generator running. Now it shows a little above 12V, even when the generator is off. I need to get a digital voltmeter there.

 

[Helmsman]

Hopefully the final conclusion has arrived. It was the ProMarine isolator. It is faulty.
The new Victron isolator has arrived, installed, and functioning. It does what I wanted the isolator to do. Sends voltage to the starting batteries 14.2V and the dctodc chargers. I set the dctodc units to lithium configuration and the incoming 14.2V is sent out as 13.8V charging voltage to the bus bar where the lithiums are connected. This happens at any rpm on the main engine.
I have measured the voltage with a digital meter at the alternator, at the isolator terminals, at the batteries. Pretty much 14.2V everywhere.
Also, my voltmeter shows proper voltage in the PH. Same as it was with generator running. Now it shows a little above 12V, even when the generator is off. I need to get a digital voltmeter there.

View attachment 131093

Glad that you figured the issue out. Hopefully, it stays fixed. Appreciate you bringing the solution back to the discussion. It will be there if someone else runs into the same thing.