Problem with Pylontech SOC after SmartSolar upgrade to 1.42

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Mikael asked Aug 1, '19

Problem with Pylontech SOC after SmartSolar upgrade to 1.42

Hi

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 https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom

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 Controllers BMV Battery Monitor Pylontech Venus GX - VGX

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Mikael answered · Aug 28, 2019 at 03:57 AM

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

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Daniël Boekel (Victron Energy Staff) ♦♦ commented · Aug 28, 2019 at 07:15 AM

Thanks for the update @Mikael

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

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Mikael Daniël Boekel (Victron Energy Staff) ♦♦ commented · Aug 28, 2019 at 07:23 AM

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

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Modifications Space

Node Red Space

Answer 1 · 2019-08-01T10:18:53Z

Guy Stewart (Victron Community Manager) answered · Aug 01, 2019 at 10:18 AM

Hi @Mikael

An explanation of error #68 is here - https://www.victronenergy.com/live/mppt-error-codes#err_68_-_network_misconfigured

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 - https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom#my_system_only_charges_the_battery_to_52v

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 commented · Aug 01, 2019 at 10:39 AM

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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Guy Stewart (Victron Community Manager) ♦♦ Mikael commented · Aug 01, 2019 at 11:57 AM

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 Guy Stewart (Victron Community Manager) ♦♦ commented · Aug 01, 2019 at 12:31 PM

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 Mikael commented · Aug 02, 2019 at 08:50 AM

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

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Mikael Guy Stewart (Victron Community Manager) ♦♦ commented · Aug 21, 2019 at 01:54 PM

I still have declining SOC. Is this really normal?

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Mikael Guy Stewart (Victron Community Manager) ♦♦ commented · Aug 22, 2019 at 03:55 PM

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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