Is My Victron Multi Dying ?

[s/v Jedi]

John,

The talk about high battery resistance doesn't make any sense because the charger output voltage would quickly go up to 14.4V or whatever setting it is at and switch the charger to absorption phase.

Bulk phase, per definition, means maximum current output by raising the voltage as the battery fills up, until that voltage set point for absorption phase is reached, after which the voltage is held at that point and the current is allowed to decrease. This is not what is happening, meaning the charger does not produce it's rated output. There might just be a FET malfunctioning or something, but I don't see a local island electrician fix that.

Instead of keeping trying this futile charging failure, start charging using the engine and measure current AND VOLTAGE. If that voltage goes up to well above 14V before amperage tapering off, it provides proof that the battery is charged okay from the alternator, so that we can eliminate a set of possible problems.

cheers,
Nick.

[Dockhead]

That's good advice. Another thing to eliminate -- just to be sure -- would be the batteries. I would perform this experiment: Disconnect your house batteries at the charger and connect the charger to a known good battery using different cables. I agree with Nick that it seems hard to imagine that the batteries could be causing it, but why not eliminate it. This experiment will eliminate the cabling as well.

My wild guess -- although I bow to the vastly superior knowledge of people like Nick -- is that the charger is bad or improperly configured. I can't think of any single external factor which would cause the charger to taper off the current prior to ramping up the voltage. But since bench testing the charger is the most difficult diagnosis you could perform, I would eliminate everything else first.

I have Victron gear on my boat and while it is pretty and has excellent functionality, I am not sure that it is very reliable. I have myself had a total failure of a Victron isolation transformer in only a year of use. The marine electrician in Cowes -- a guy respected all over the south coast here -- sells, installs, and services Victron equipment, but tells me that it fails with great frequency. He tells me that the el-cheapo crappy Sterling gear which he also sells actually fails much less often (of course, it is much simpler, which may be part of the explanation).

So I would not be at all surprised if something inside your unit as given up the ghost. But, eliminate everything else before coming to that conclusion. If the charger does the same thing on shore power as it does on your generator's power, and if it does the same thing with a different battery connected with different cables, then you can be sure it's the charger.

[Dreaming Yachtsman]

I am now plugged into shore power at Crown Bay Marina so I am breathing a little easier but still not exactly happy. Charge voltage from the main engine alternator was 13.8 V, current 30 amps at idle. I didn't have a chance to monitor the battery during the transit as we had wind gusts to 25 knots, going through a narrow cut with rocks on both sides, and dodging a boat with divers in the water.

After plugging into shore power and energizing the battery charger, its output was 14.02 V, 53 amps. This was after the main engine charged with its alternator for about 1/2 hour. Interestingly both bulk and absorption LED's were on steady, indicating "The mains voltage is switched through and the charger is charging. The set absorption votage, however, has not yet been reached" per Owner's Manual. Half an hour later, output was 13.37 V and 25.3 A, both LED's still burning.

After another half hour (now) I'm seeing 13.65 V and 23.4 A. Both LED's still burning.

Dockhead, welcome to the fray and thanks for your comments concerning Victron equipment. I suppose 8 years of faithfull service without a failure is not asking too much. I have thought about chucking this whole unit and replacing it but have not taken that step yet.

Going to lunch now. Will see what the charger is doing after that and how to hook to another battery.

[Dreaming Yachtsman]

Originally Posted by s/v Jedi

John,

The talk about high battery resistance doesn't make any sense because the charger output voltage would quickly go up to 14.4V or whatever setting it is at and switch the charger to absorption phase.

.......

Instead of keeping trying this futile charging failure, start charging using the engine and measure current AND VOLTAGE. If that voltage goes up to well above 14V before amperage tapering off, it provides proof that the battery is charged okay from the alternator, so that we can eliminate a set of possible problems.

cheers,
Nick.

Nick,

I agree with you 100% about the battery resistance and proper charger behavior. I'll do the engine charge and battery swap tests after lunch. I can't think well on an empty stomach.

[s/v Jedi]

Oh my... never listen to what the salesmen tell you. They will always advice you to buy what makes them the most money.

I see very little errors/failures with Victron. Much less than with MasterVolt and unbelievably less than with Xantrax.

ciao!
Nick.

[Dreaming Yachtsman]

On one hand, I am very happy because the Victron is now working as it is supposed to - Battery voltage is 13.2, charging amps are 28, increasing in bulk charge mode. On the other hand, I don't know what we did to fix the problem so I very much dread a recurrence.

After lunch I depowered the Victron AC side and started the stbd main engine to recharge the house batteries per Nick's suggestion to rule out the batteries as a problem. I'm not sure my test did that, though because of the following numbers:
Time Volts Amps
1400 13.96 26 Engine at 1800 RPM, All DC loads off
1405 13.88 23.3 Engine at 1500 RPM and all subsequent readings
1410 13.83 22.8
1415 13.81 22.5
1420 13.79 21.9
1425 13.78 21.5
1430 13.77 21.2
I can rationalize the slowly decreasing voltage by heating in the alternator as it was uncomfortably warm to touch but not searing hot.

Shortly after I stopped this test, Chris, an electrician at the Crown Bay Boatyard, showed up in response to my earlier call. I described the symptoms to him but by then the battery apparently was charged enough that Victron decided to play nice. When he turned the unit off, then back on it quickly cycled through to float as would be expected for a nearly fully charged battery.

This is where it becomes interesting. We turned off power to the charger and ran the microwave on inverter for four minutes then repowered the charger. Much to my astonishment and delight, it went into bulk charge mode and the voltage kept increasing. It is now at 13.95 volts, 26 Amps.
Plan is to let the present charge complete to float then turn off power to the charger to run loads off the inverter overnight. Chris will come back first thing in the morning to watch the charge we will initiate then.

My unanswered questions are:
- What caused the maloperation in the first place?
- What changed to fix it?
- When will it happen again? (This answer, according to Murphy's Law, is at the worst possible moment, in this case on a dark and stormy night miles away from shore on a wildly heaving sea . . . . . )(Oops, wrong thread for that!)

[btrayfors]

John,

Where, exactly, are you measuring the voltages? And, with what? The Exetech with leads on it? Do you have any other way to confirm that the readings are accurate?

These voltages are still too low. You should be seeing in excess of 14.4VDC in bulk and absorption phases.

You can't really be sure what's going on until you charge those batteries FULLY.

Bill

[FlyingCloud1937]

Originally Posted by Dreaming Yachtsman

O
This is where it becomes interesting. We turned off power to the charger and ran the microwave on inverter for four minutes then repowered the charger. Much to my astonishment and delight, it went into bulk charge mode and the voltage kept increasing. It is now at 13.95 volts, 26 Amps.
Plan is to let the present charge complete to float then turn off power to the charger to run loads off the inverter overnight. Chris will come back first thing in the morning to watch the charge we will initiate then.

My unanswered questions are:

- What caused the maloperation in the first place?
- What changed to fix it?

Let's see,...your are now plugged into the shore grid, so that means you have by-passed the generator, as well as the auto-former

- When will it happen again? (This answer, according to Murphy's Law, is at the worst possible moment, in this case on a dark and stormy night miles away from shore on a wildly heaving sea . . . . . )(Oops, wrong thread for that!)

The next time the battery bank goes below 40%SOC, and you try to charge from the generator feeding the autoformer, which is feeding the charger, the HW heater, the refrigeration, the freezer, plus AC incidental loads, plus drawing what amps on the dc side all at the same time.

And then wondering why the bat voltage won't come up after only an hours generator run time.

Lloyd

[Dreaming Yachtsman]

Originally Posted by btrayfors

John,

Where, exactly, are you measuring the voltages? And, with what? The Exetech with leads on it? Do you have any other way to confirm that the readings are accurate?

Measured with Extech digital meter at one of three places that give relatively equivalent values:
1. Terminal connections on the Victron itself
2. Battery posts on the most accessible pair
3. The installed digital voltmeter which is wired across the most difficult to access pair
Thus far I have not been going for super accuracy but rather looking for trends. I plan to check absorption setpoints tomorrow am. I do have another cheap multimeter but haven't seen the need to use it.

Originally Posted by btrayfors

These voltages are still too low. You should be seeing in excess of 14.4VDC in bulk and absorption phases.

Agreed, which is one reason for checking setpoints before declaring victory.

Originally Posted by btrayfors

You can't really be sure what's going on until you charge those batteries FULLY.

Bill

[Dreaming Yachtsman]

Originally Posted by FlyingCloud1937

Let's see,...your are now plugged into the shore grid, so that means you have by-passed the generator, as well as the auto-former

The next time the battery bank goes below 40%SOC, and you try to charge from the generator feeding the autoformer, which is feeding the charger, the HW heater, the refrigeration, the freezer, plus AC incidental loads, plus drawing what amps on the dc side all at the same time.

And then wondering why the bat voltage won't come up after only an hours generator run time.

Lloyd

You seem to have a hard spot for the generator and transformer as being the culprits. Many times in the past 4 days of this adventure when the charger would not bring up battery voltage, it was the only AC load on the generator, drawing about 6 amps 110VAC. In the past, I could heat water AND charge the batteries at the same time for a total of nearly 20 amps 110 VAC with the generator barely even warming up. Granted when fully loading the generator with 2 A/C plants, charging results were not so good as the cycling compressors would kick off the charger.

BTW, refrigerator and freezer are DC loads, not that it changes the discussion much.

The fundamental reason the battery voltage would not come up is that the charger was not maintaining voltage at its output. I still don't understand why not and that is what makes me very nervous about declaring victory.

I fully intend to charge from the generator tomorrow with the local electrician present to observe first hand. If Victron behaves as it should, I'll go on my way. If not, back to troubleshooting.

[s/v Jedi]

Exactly, that genset does 50 amps at 120V with ease. and I think you are still on genset... or did you get a slip now?

cheers,
Nick.

[colemj]

Originally Posted by Dreaming Yachtsman

On one hand, I am very happy because the Victron is now working as it is supposed to - Battery voltage is 13.2, charging amps are 28, increasing in bulk charge mode. On the other hand, I don't know what we did to fix the problem so I very much dread a recurrence.

It is not fixed. Those are entirely inappropriate values. 13.2V is a float voltage, if even that, and in float mode the amperage output should be 1-2 amps at most. If the 13.2V is during bulk mode while still increasing in voltage, the amp output should be much higher than 28 - more like 80-100A. If the 28 amps are while it is in absorption mode, then the voltage should be 14.4-14.8V.

There is no proper working condition that will give you 13.2V and 28A.

Mark

[Dreaming Yachtsman]

Originally Posted by s/v Jedi

Exactly, that genset does 50 amps at 120V with ease. and I think you are still on genset... or did you get a slip now?

cheers,
Nick.

Sorry if I neglected to mention it but I am in a slip at Crown Bay Marina.

[Dreaming Yachtsman]

Originally Posted by colemj

It is not fixed. Those are entirely inappropriate values. 13.2V is a float voltage, if even that, and in float mode the amperage output should be 1-2 amps at most. If the 13.2V is during bulk mode while still increasing in voltage, the amp output should be much higher than 28 - more like 80-100A. If the 28 amps are while it is in absorption mode, then the voltage should be 14.4-14.8V.

There is no proper working condition that will give you 13.2V and 28A.

Mark

Mark,

A half an hour after I wrote those numbers, I noted 13.95 volts and 26 amps charging. By the time I got back from lunch, it was on float. We'll see what happens tomorrow morning. Can you feel the suspense building?

[colemj]

Originally Posted by Dreaming Yachtsman

Mark,

A half an hour after I wrote those numbers, I noted 13.95 volts and 26 amps charging. By the time I got back from lunch, it was on float. We'll see what happens tomorrow morning. Can you feel the suspense building?

If you have flooded batteries with a SOC less than 80%, you should see 14.6-14.8V (temp compensated) during bulk, at which time the current should be higher than 60A. During absorption, the voltage should stay the same and the current should ramp down to 10 amps or so. During float, the voltage should be at 13.6-13.8 (temp compensated) and the current less than 5V.

None of your readings match these expectations.

What is your current right now on float? If it is still above 5A, and you do not have large DC loads operating, your batteries are not in float regardless of what the charger is telling you.

None of the voltage and amperage values you have stated since the start of the thread match an expected charging regime at any time. Regardless of having new batteries or a weak genset or a bad transformer or any other issue.

I think your charger is bad.

Mark