Alternator does not revert to charging after initial charging.

[bensolomon]

Good afternoon. I have a balmar 100 amp alternator, and a new balmar mc 614 regulator. Just did a long passage steaming (30 hours). After my battery was fully charged by the alternator, I thought everything was all good. I checked the battery levels all through the night, and noticed the levels continuing to drop. At 11.8 volts, I shut down, and restarted the engine to initiate charging, which it did just fine. I have read the regulator manual and my questions are:

Which one of the charge threshold values needs adjusting to get started charging while the engine is running without having to restart? Is it the Low Voltage Limit or one of the field thresholds?

Thank you,
Ben

[smac999]

Yiu should not have to do anything. The alt should just continue to float at ~13.5v once full.

Is the alt directly connected to the battery yiu are measuring?

[bensolomon]

It's connected through an isolator switch.

[DeepFrz]

Please explain what you mean by "isolator switch". I've not heard that term used before.

[sailinglegend]

Originally Posted by DeepFrz

Please explain what you mean by "isolator switch". I've not heard that term used before.

It sounds like the alternator is charging the starter battery and measuring the voltage of the starter battery, but the 'isolator' is initially charging the house bank and then switching itself off. The 'isolator' should be dual sensing to measure the voltage of both banks that need charging so when the house bank falls below say 12.8v then the 'isolator' will charge both banks again.

Starter batteries don't need charging first because they could start the engine 10 times before they need charging as only about 1% of their capacity is used on each start. So the output of the alternator should go to the house bank first and this model of 'isolator' might then work for you.

[bensolomon]

Originally Posted by sailinglegend

It sounds like the alternator is charging the starter battery and measuring the voltage of the starter battery, but the 'isolator' is initially charging the house bank and then switching itself off. The 'isolator' should be dual sensing to measure the voltage of both banks that need charging so when the house bank falls below say 12.8v then the 'isolator' will charge both banks again.

Starter batteries don't need charging first because they could start the engine 10 times before they need charging as only about 1% of their capacity is used on each start. So the output of the alternator should go to the house bank first and this model of 'isolator' might then work for you.

I see you have a Hunter, as well. I have always admired the Passages. I suspect what you are describing is the case. I have this emergency cross connect "key" plus the House/Engine switch, as well. I am not familiar enough with marine electricity and wiring to tease this out. And, I suspect this is wired through the shunt for shore power charging.

How would I go about teasing this all out?

Thanks,
Ben

[hlev00]

I encountered this exact problem with the ASR-5. Definitely contact Balmar, they know their gear the best.

You should get the data for battery temp and alternator temp. It may require enabling long output mode. In my case we believe that the battery temperature was resulting in zero amps charging. My Beneteau's batteries are located in the engine room and I discovered through this process that my blower has never worked. I didn't know there was one. The alternator was also scorching hot during this. I found that by disconnecting the battery temperature sensor that the regulator once again let the charging commence. The output was reduced due to the alternator temperature, but it did continue to deliver amps. I have since fixed the blower but not yet done a complete test to validate. One setting worth changing is how often the regulator checks to see if it needs to change modes. Default should be 18 minutes. The minimum is 6 minutes. Balmar recommended that I change to 6 minutes. They said even at 18 minutes there is no danger of damaging the batteries.

Harry
https://juno423.blogspot.com

[bensolomon]

Harry,

Thank you for this! I thought this may be my problem, as well. I have a infrared pyrometer on board and during my trip I was checking engine temps. my battery bank is located directly above my engine compartment. My alternator was almost 200 degrees and the engine was running at 189.

I will check all of this out when I'm back on the boat next weekend.

Thank you!