Balmar Max Charge MC-612 Question

[Maine Sail]

Originally Posted by dksail

The actual voltage was 13.2 and was verified manually with a Fluke at the alternator. The bulk and absorption modes were programmed at 14.4.

I checked the voltage sensor wiring and the manual gives you the option to connect it to the alternator positive lead which it is. That is where I measured the 13.2 but regulator was reading 14.3.

Read the article above your sensing is incorrect for LFP and needs to include regulator B-...

[dksail]

Maine Sail: thanks so much, what an article! I will give that a try.

[smac999]

if you are measuring 13.4v at the same voltage sense pos and ground wire as the regulator. but it's showing a BV reading of 14.3v. them I'm guessing the balmar is hooped.

make sure you are using the same ground to measure and make sure everything is clean and tight. inlcuding the big black plug on the balmar.

[dksail]

Update: more testing, still more questions. So to remind all of the issue...

Test conditions: resting battery voltage 13.4 (Some solar)
Battery capacity down 15% or 60 amp/hrs
Target Voltage: 14.4

When the key is on, motor off, the regulator reads the battery voltage correctly, around 13.4V this morning.

When I start the engine and wait for the 45 seconds, the voltage sense reading climbs to 14.1V within just a matter of a minute. The actual battery voltage is still at 13.4V measured with a multi-meter and a Victron bvm.

The alternator puts out about 10 amps at idle. Increasing rpm to 2000, no change in amps.

I measured the voltage at the alternator positive with the same ground as the voltage sense and it reads 14.1V. Is this normal? Testing to engine as ground was 14.1 as well.

I replaced the voltage sense wire with a new wire running directly to the battery reducing voltage loss and that had no impact, the voltage sense was still reading 14.1V.

This last test indicates to me that the voltage sense on the regulator is bad. Thoughts?

[Maine Sail]

Originally Posted by dksail

This last test indicates to me that the voltage sense on the regulator is bad. Thoughts?

Were is regulator B- (black wire in Ford plug) wired to? Reg B- is the other HALF of the voltage sensing circuit. If the + v-sense wire was bad the regulator should not operate.

[dksail]

The B- wire is attached to the alternator at the ground terminal. I don’t think the wire is bad, it is just not reading Bv correctly.

[CharlieJ]

dksail: Per Maine Sail's article, for total accuracy the regulator B- must be connected at the battery B-. It will work if connected to the alternator B-, just not as well.

[dksail]

Thanks Charlie, I was thinking for a test, getting rid of half the problem would tell me something. If I get a new one, that advice is good!

[wingssail]

Originally Posted by dksail

Update: more testing, still more questions. So to remind all of the issue...

Test conditions: resting battery voltage 13.4 (Some solar)
Battery capacity down 15% or 60 amp/hrs
Target Voltage: 14.4

When the key is on, motor off, the regulator reads the battery voltage correctly, around 13.4V this morning.

When I start the engine and wait for the 45 seconds, the voltage sense reading climbs to 14.1V within just a matter of a minute. The actual battery voltage is still at 13.4V measured with a multi-meter and a Victron bvm.

The alternator puts out about 10 amps at idle. Increasing rpm to 2000, no change in amps.

I measured the voltage at the alternator positive with the same ground as the voltage sense and it reads 14.1V. Is this normal? Testing to engine as ground was 14.1 as well.

I replaced the voltage sense wire with a new wire running directly to the battery reducing voltage loss and that had no impact, the voltage sense was still reading 14.1V.

This last test indicates to me that the voltage sense on the regulator is bad. Thoughts?

I recently had a problem with Balmar regulator reading incorrect Bv (different specific error, but incorrect Bv reading causing improper alternator output).

After all of your testing and diagnostics, a good test is to install the spare regulator(which is a good item to carry). It is unlikely that two regulators would have the same voltage sensing error HOWEVER it is not impossible. With a dual output alternator, such as a series 90-110 with two positive output posts, some combination of diode failure or misbehavior I think could cause the programming in the regulator which would cause it to incorrectly calculate the Bv. In fact, I have reason (based on personal experience) to believe that such an alternator diode condition could cause permanent error in the regulator which would be un-resolved even when the alternator itself is changed.

I have recently sent two Balmar regulators to Alabama for analysis regarding why the voltage sensing program seemed to be incorrect. A new alternator and a new regulator solved the problem. No wiring changes and no programmed settings had any effect.

[dksail]

Thanks Wingsail. Hopefully Balmar will tell me something interesting on Monday. I think a spare is a good idea as I just replaced a bad Duo Charge last month, with a spare. While not used much, this MC 612 is at least 13 years old.

[smac999]

Originally Posted by dksail

Update: more testing, still more questions. So to remind all of the issue...

Test conditions: resting battery voltage 13.4 (Some solar)
Battery capacity down 15% or 60 amp/hrs
Target Voltage: 14.4

When the key is on, motor off, the regulator reads the battery voltage correctly, around 13.4V this morning.

When I start the engine and wait for the 45 seconds, the voltage sense reading climbs to 14.1V within just a matter of a minute. The actual battery voltage is still at 13.4V measured with a multi-meter and a Victron bvm.

The alternator puts out about 10 amps at idle. Increasing rpm to 2000, no change in amps.

I measured the voltage at the alternator positive with the same ground as the voltage sense and it reads 14.1V. Is this normal? Testing to engine as ground was 14.1 as well.

I replaced the voltage sense wire with a new wire running directly to the battery reducing voltage loss and that had no impact, the voltage sense was still reading 14.1V.

This last test indicates to me that the voltage sense on the regulator is bad. Thoughts?

Which battery is the alternator connected too? Direct to house? This kinda sounds like it’s charging and sensing an engine battery. And not the house. The engine batt is probably at 14.1v. And the house stays the same.

[dksail]

That thought crossed my mind too, good question. All of my charging sources charge my house bank and the remaining batteries get charged from B2B chargers. But, with your question, I triple checked and found it is looking at house batteries.

[sailorboy1]

Maybe it is just that the regulator has gone bad, it happens. If nothing has changed, the wire connections have been cleaned and checked, and you have a regulation problem that starts out OK but goes "bad" after a few minutes I would be thinking the regulator is the problem.

Without me looking, does the regulator have a factory reset (I believe it does as the ARS-5 does). Have you tried resetting it and seeing what it does after?

[dksail]

That is on my list of Balmar questions for tomorrow hopefully. Nothing in the manual on a reset, but it seems like a feature that should exist.

[waterman46]

Originally Posted by dksail

Update: more testing, still more questions. So to remind all of the issue...

Test conditions: resting battery voltage 13.4 (Some solar)
Battery capacity down 15% or 60 amp/hrs
Target Voltage: 14.4

When the key is on, motor off, the regulator reads the battery voltage correctly, around 13.4V this morning.



No current is flowing in the charge circuit, so no voltage drop is possible, and the voltages will be the same.


When I start the engine and wait for the 45 seconds, the voltage sense reading climbs to 14.1V within just a matter of a minute. The actual battery voltage is still at 13.4V measured with a multi-meter and a Victron bvm.


Same ground point used in all measurements? If not, repeat with same ground point for the voltmeter, probably best right at alternator.



The alternator puts out about 10 amps at idle. Increasing rpm to 2000, no change in amps.

I measured the voltage at the alternator positive with the same ground as the voltage sense and it reads 14.1V. Is this normal? Testing to engine as ground was 14.1 as well.

I replaced the voltage sense wire with a new wire running directly to the battery reducing voltage loss and that had no impact, the voltage sense was still reading 14.1V.


If there is a good wire connection from battery positive to regulator voltage sense terminal, and your batteries have a good ground connection to the alternator negative, you should (actually must) have nearly the same voltage readings at the battery as at the voltage sense terminal of the regulator. Until you get the same voltage on the sense as you have at the batteries, any other actions are fruitless.


This last test indicates to me that the voltage sense on the regulator is bad. Thoughts?

You could be correct, if there was abnormally high current being drawn by the sense terminal of the regulator, causing voltage drop in the sense wire. Can you measure the current in the sense wire?