Mikael avatar image
Mikael asked

Problem with Pylontech SOC after SmartSolar upgrade to 1.42


After remotely from VRM upgrading SmartSolar to 1.42 my battery doesn’t get charged fully. It charges to example at 92% and today 89% and then just stops and only matches the solar yield to the DC consumption even when there is lots of sun.

I got an error “#68 Network misconfigured” from the SmartSolar after upgrade so I had to exclude it from the SmartNetwork. That is clearly show on the graphs as the big dip starting 2019-04-24.

Both times it has got back to SOC 99 or 100% was after a shutdown and power off whole system and starting it up again.

I have notice the BMV-712 in not correct in SQC and stated 100% when the battery is not. But the VenusGX is set to use Battery Monitor “Pylontech battery on CAN-bus”. Can it be the BMV that is still being in control of SOC in some way? SmartSolar is disconnected from the SmartNetwork but it still feels like it stops charging when BMV get near 100%

The system has been working very good until now.

I have checked the settings against

Pure DC system with 3500w PV and

VenusGX (2.33)

SmartSolar Charger MPPT 250/100 rev2 (1.42)

BMV-712 Smart (4.01)

Pylontech US2000B.

512 = Pylontech
260 = BMV-712 Smart

This is a remote location and I can only use VRM unless I take the trip there.

MPPT ControllersBMV Battery MonitorPylontechVenus GX - VGX
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2 Answers
Mikael avatar image
Mikael answered ·

The problem is now solved, it was a bad connection at one of the cables in the end.

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Thanks for the update @Mikael

To help us and others, what cable had a bad connection?

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Mikael avatar image Mikael Daniël Boekel (Victron Energy Staff) ♦♦ commented ·

The crimping on the positive cable at the SmartSolar had come lose or at least somewhat lose.

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Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @Mikael

An explanation of error #68 is here -

It is always the case that multiple SOC meters will not agree.

With the SmartSolar disconnected from the Smart Network, the pylontech battery is controlling the charge. This is interpreted by the DVCC system inside the GX device too, as explained here -

There has been a change in charging voltages to improve reliability of the system, with virtually no decrease in actual usable capacity.

While the system is behaving differently from how you have become used to, from your photos, it still appears to be working well.

I am not sure why you have a BMV, when the Pylontech provides it's own State Of Charge reading. There is no harm done with your current configuration, but it is deliberately absent from in the Pylontech and Victron manual. Having multiple States Of Charge only adds to the confusion, and in this case the integrated Pylontech is the more accurate one you should be using.

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Mikael avatar image Mikael commented ·

Thanks @Guy Stewart (Victron Community Manager)

I will disconnect the BMV tomorrow from the VenusGX and see it that helps. Just leaves it connect to the shunt but not to the Smartnetwork or VE.Direct as a stand alone device would not interfere with the rest of the system, correct?

I will try to adjust the BMV to show more correct SOC as it's a nice and quick way to see battery status without having a phone or computer at hand.

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Hi @Mikael,

Sorry if I wasn't clear, now that you have the BMV installed, it is not necessary to remove it. Now that the smart network is disabled, it will not make any difference to the behaviour you are seeing.

It is understandable to want to have a clear state of charge display, though in my opinion this is best done with the colour control gx ;)

Now, with the equipment you have, I would suggest playing with the parameters of the BMV to more closely match the reading of the Pylontech. It would seem from your image that it is resetting to 100% too soon, so perhaps extending the time required, or raising the voltage point threshold in the BMV.

No rush on that though, and no need to make a special trip out to your remote site.

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Mikael avatar image Mikael Guy Stewart (Victron Community Manager) ♦♦ commented ·

But the SOC keeps dropping on the Pylontech battery that is my main concern. I can see this become a problem soon. Why do the charging stop at 89% today, it's still plenty of sun so it could continue to charge more. Yesterday is stopped at 92%. I want to understand why the system is doing this. Are you saying that it should do this?

The battery voltage is now at 50,98V, I would expect it to be at 52V:ish or?

I still believe unplugging the VE.Direct cable from the BMV will make a differens :-) It's to much of a coincident that the VenusGX stops charging when BMV reaches 100% SOC.

But I understand what you mean but I feel that it's to much differens. If so the SOC should slowly be increasing from the 89% where it stopped this morning, but it hasn't. I will keep monitoring and see what happens.

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Mikael avatar image Mikael Mikael commented ·

Of course you where correct. Completely removing the BMV did not make any different at all. :-)

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Mikael avatar image Mikael Guy Stewart (Victron Community Manager) ♦♦ commented ·

I still have declining SOC. Is this really normal?

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Mikael avatar image Mikael Guy Stewart (Victron Community Manager) ♦♦ commented ·

Even more obvious here on 90 days graph.

Any ideas on what I can do to correct this. I am getting worried as the SOC is getting lower each day even when there are no load to speak of :-(

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