Low voltage alarm Balmar 60 series & MC 614

[Sam Woodbridge]

Been trying to figure it out for months. Even called Balmar tech support. Any thoughts would be sincerely appreciated.

The engine is a Yanmar 3YM30AE with a Balmar 60 series 120 amp alternator and a MC 614 external regulator.

On occasion I’ll put the boat in neutral and my no charge alarm goes off. Not all the time but sometimes. I’ve noticed when that happens my house batteries will drop below 12.7 volts and that is what causes the alarm. They usually go down to 12.5 - 12.4 the alarm goes off for 10 seconds or so or until I raise the idle. It’s a annoying thing. My guess was the idle is set to low and the alternator kicks out due to low rpm.

Balmar tech support pretty much verified what I was thinking. And that a solution would be to go into advance settings in the MC 614 and change the low voltage to something else. Such as 12.1 volts.

I keep thinking in my mind that isn’t the correct fix and neither is raising the idle. As Balmar said there alternators will sometimes need at least 1,000 rpms to charge. I’m to the point now wondering if Balmar has the correct size pulley on there alternator for my engine.

Any thoughts would be appreciated and if I get any replies to the thread I’ll be sure and reply back tomorrow as it’s getting late.

[Paul L]

You don't say what type of batteries you have. If they are standard lead-acid, agm or gel then there's nothing wrong with the voltages dropping to 12.4v.
Did you set the alarm at 12.7?

[Emmalina]

Check the type of batteries on the Balmar is correct. The pulley ratio is normally about 2 to 1 so 750 tickover should be 1500 on the alt !

[Sam Woodbridge]

Originally Posted by Paul L

You don't say what type of batteries you have. If they are standard lead-acid, agm or gel then there's nothing wrong with the voltages dropping to 12.4v.
Did you set the alarm at 12.7?

Thank you for the reply Paul.

The batteries are AGM. The MC 614 is programmed for them.

MC 614 low voltage alarm is factory set at 12.7. And I can change it to whatever I want.

[Sam Woodbridge]

Originally Posted by Emmalina

Check the type of batteries on the Balmar is correct. The pulley ratio is normally about 2 to 1 so 750 tickover should be 1500 on the alt !

Thank you Emmalina.

Yes the setting on the MC 614 is correctly set for AGM. (Batteries in my boat)

I really like your pulley comment. It’s what I’m leaning towards. But all in all - I changed the low voltage from 12.7 to 12.1. and I’ll probably never hear it again. I just don’t feel that’s the correct fix.

[ikanode]

12.7V is way too low for a low voltage alarm.

There's a SOC chart for AGMs at REST on: https://marinehowto.com/under-load-b...oltage-vs-soc/
(These voltage charts are just estimates.)

The voltage under load depends on the size of the load!

12.7 with a load is probably above 90% full
12.1 with a load is probably above 50-60% full

I don't know if your system is set up perfectly but I don't see a problem having the low voltage warning set at 12.1v. You may want to monitor your battery voltage while the engine is running and after the battery rests overnight.

[Sam Woodbridge]

Originally Posted by ikanode

12.7V is way too low for a low voltage alarm.

There's a SOC chart for AGMs at REST on: https://marinehowto.com/under-load-b...oltage-vs-soc/
(These voltage charts are just estimates.)

The voltage under load depends on the size of the load!

12.7 with a load is probably above 90% full
12.1 with a load is probably above 50-60% full

I don't know if your system is set up perfectly but I don't see a problem having the low voltage warning set at 12.1v. You may want to monitor your battery voltage while the engine is running and after the battery rests overnight.

Thank you Ikanode,

You got to love marine how to. I’ll fully read that article. I really like the chart he has for AGM batteries. I took a screen shot of it with my phone.

I have monitored the system over night after a full charge. Everything works as it should.

And keep in mind the MC 614 is factory set at 12.7 for a low voltage alarm, but it can be changed to any amount. Which I did and I’m close to leaving this problem alone. After changing the low voltage alarm to 12.1.

[hlev00]

@IKANODE - those are for when the battery is not under load.


OP - The pulley sounds like a fix for the symptom, but not for the problem. What else is drawing power at that time? It might be useful to check the connections on the battery. A poor connection will cause more resistance, lowering the voltage until the alternator starts making up for the loss. Check if the connections are warmer that the ambient for their location. An infrared thermometer can be useful for this. If you have a ground stud on the engine temperature won't help but still inspect and clean.

[MJH]

Originally Posted by Sam Woodbridge

Been trying to figure it out for months. Even called Balmar tech support. Any thoughts would be sincerely appreciated.

The engine is a Yanmar 3YM30AE with a Balmar 60 series 120 amp alternator and a MC 614 external regulator.

On occasion I’ll put the boat in neutral and my no charge alarm goes off. Not all the time but sometimes. I’ve noticed when that happens my house batteries will drop below 12.7 volts and that is what causes the alarm. They usually go down to 12.5 - 12.4 the alarm goes off for 10 seconds or so or until I raise the idle. It’s a annoying thing. My guess was the idle is set to low and the alternator kicks out due to low rpm.

Balmar tech support pretty much verified what I was thinking. And that a solution would be to go into advance settings in the MC 614 and change the low voltage to something else. Such as 12.1 volts.

I keep thinking in my mind that isn’t the correct fix and neither is raising the idle. As Balmar said there alternators will sometimes need at least 1,000 rpms to charge. I’m to the point now wondering if Balmar has the correct size pulley on there alternator for my engine.

Any thoughts would be appreciated and if I get any replies to the thread I’ll be sure and reply back tomorrow as it’s getting late.

My boat has a Balmar alternator (712-110) and MC-614-H regulator with a Volvo-Penta D2-55B engine and 8D Gel batteries.

I assume your sound alarm is setup via the MC-614 DASH LAMP feature...I have mine setup to a red light. When I was getting activity on the light I called Balmar; it turned out to be a bad cable that needed to be replaced.

However, those alerts had nothing to do with my "battery" status at the time...I don't understand the wide swings in your battery voltage with RPM change. How old are your batteries and/or do you have a heavy load on them when the alarm sounds?

~ ~ _/) ~ ~ MJH

[Primal Alliance]

I'm not a diesel mechanic. I'm a medical doctor. But I've owned my YM 20 for 14 years and replaced the smaller Yanmar alternator that it came with with a big Balmar. I have experienced no tach read out until the alternator kicks in. It has a delay in doing so to protect either the engine from overload when it first starts up, or the alternator. I don't know which. But if this is only a problem at start up, and I'm assuming its more than that, ignore it.

[Sam Woodbridge]

Originally Posted by hlev00

@IKANODE - those are for when the battery is not under load.


OP - The pulley sounds like a fix for the symptom, but not for the problem. What else is drawing power at that time? It might be useful to check the connections on the battery. A poor connection will cause more resistance, lowering the voltage until the alternator starts making up for the loss. Check if the connections are warmer that the ambient for their location. An infrared thermometer can be useful for this. If you have a ground stud on the engine temperature won't help but still inspect and clean.

Thank you Hlev00,

I have a temperature gun and will look at the connections. It’s a good idea.

[Sam Woodbridge]

Originally Posted by MJH

My boat has a Balmar alternator (712-110) and MC-614-H regulator with a Volvo-Penta D2-55B engine and 8D Gel batteries.

I assume your sound alarm is setup via the MC-614 DASH LAMP feature...I have mine setup to a red light. When I was getting activity on the light I called Balmar; it turned out to be a bad cable that needed to be replaced.

However, those alerts had nothing to do with my "battery" status at the time...I don't understand the wide swings in your battery voltage with RPM change. How old are your batteries and/or do you have a heavy load on them when the alarm sounds?

~ ~ _/) ~ ~ MJH

Thank you MJH

How did you find your bad cable?

My batteries are 3 years old.

A heavy load on the batteries? No not that I’m aware of. It happens randomly. For instance I motor out of the marina. I place the boat in auto pilot pointing into the wind. Roll out my sails. Place the boat into neutral and the alarm comes on. It’s still in auto pilot. Sometimes the volts pick back up in 10 seconds and the alarm goes away. Other times I’ll raise the idle and it goes away. Other times I turn the engine off.

I like the idea of a bad cable somewhere. It’s just that the boat is a 2018 with 165 engine hours. I’ve owned the boat for 6 months and had always had this problem. I’m sure it was sold to me with them knowing it too. At least I assume that.

[MJH]

To answer your question:

When I spoke with Balmar and told the tech the readings I was getting on the MC-614 and my battery status, I believe he suggested that it might be the cable.

As you did not do the install I suggest that you download a copy of the manual and check all connections to the MC-614 regulator (don't assume the previous owner did a correct install).

Again, that doesn't answer the fluctuating voltage your getting. Something isn't right there beyond that alarm. There have been stories of folks with early failing AGM batteries. I would check them out as well.

Good Luck.

~ ~ _/) ~ ~ MJH

[Sam Woodbridge]

Originally Posted by MJH

To answer your question:

When I spoke with Balmar and told the tech the readings I was getting on the MC-614 and my battery status, I believe he suggested that it might be the cable.

As you did not do the install I suggest that you download a copy of the manual and check all connections to the MC-614 regulator (don't assume the previous owner did a correct install).

Again, that doesn't answer the fluctuating voltage your getting. Something isn't right there beyond that alarm. There have been stories of folks with early failing AGM batteries. I would check them out as well.

Good Luck.

~ ~ _/) ~ ~ MJH

Thank you MJH

Yes I have a copy of the MC 614 manual and have rewired wires that where incorrectly installed. Although it didn’t change anything, besides me knowing it’s wired as it’s suppose to be.

And yes I agree with you something is out of sorts. I like the idea of checking the cables and will do so.

[smac999]

How is the alternator wired? Direct to house bank? Still to engine bank? With acr? With battery isolator? Where is the Regulator voltage sense connected?

It could be something simple like the acr Uncombining in idle so only one bank is charging. You need to look at the whole system.

I would not adjust to 12.1. That means if your alt fails. You will not be notified untill your batteries are 50% dead. You want to know Right when it fails. Which is why it’s set to 12.7.

If the bank is droping below 12.7 with the engine running either you have a decent load or the batteries were pretty low to start with. Even if you shut the engine off it should not be at 12.4 Unless the batteries were at ~65% or you had a big load. Or the batteries were bad.

Have you measured the amp output of the alt at idle? You should get something. It just won’t be big. Maybe 10-20a