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catarina-isabel avatar image
catarina-isabel asked

MPPT Production Drops When Battery 100%

Good afternoon everybody.

I have a victron system composed by: ET112 energy meter, 150/35 regulator, cerbo gx, multiplus II 48/3000 and a 3.5kWh battery from Dyness.

The system is configured so that in case of a grid failure, I have electricity at home, and I sell the excess as soon as the batteries are charged.

When the battery charge reaches 100%, the MPPT reduce abruptly the prodution, even though it's very sunny. Whenever I have good sunny days, as soon as the battery is charged, production drops.

Can you please help me?

captura-de-ecra-2024-01-24-164744.png

Multiplus-II150/35
captura-de-ecra-2024-01-24-164744.png (38.0 KiB)
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6 Answers
cmorewood avatar image
cmorewood answered ·

I have the same frustrating problem and in looking for an answer I found this.

https://community.victronenergy.com/questions/237470/cerbo-gx-bug-mppt-stops-power-production-in-ess-wh.html

I'm no expert, but it would be nice if one of the forum Technical engineers could take a look at it and tell us if it was the answer.

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nickdb avatar image
nickdb answered ·

There could be many reasons.

Does the system show an ESS or state code at these times?

Any limits configured in ESS?

More detail is needed.

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jetlag avatar image
jetlag answered ·

Is "Export excess DC Power" activated in the ESS settings? And if yes, is there maybe a limit set?

If it's not activated, the MPPT will only deliver that much power, that is just needed by the Multiplus2.

So please check this first.

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cmorewood avatar image
cmorewood answered ·

Thanks for the quick replys. No error codes.

I have 2 MPPTs running 2 strings on the same roof. No shading. One is an MPPT 250/60 REv2 and the other a 100/20. The latter will, as soon as the batteries reach 100% SOC, stop producing any power. The former will continue producing and exporting.

As far as I can see they are set up in the same way and I can't see any reason for the difference.

I don't remember having this problem last year.

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nickdb avatar image nickdb ♦♦ commented ·
MPPT's don't load balance so if power demands drop, you can see one work and another not, it isn't spread across chargers evenly.

If ESS min SOC is set to 100% you can also see production issues at full charge, so that is never a good idea, but you would see ESS #1 displayed on the console and VRM.

Make sure you're not mixing wired and ve smart networking.

Also check that both have the same settings and profile and you see the same voltages at their terminals.


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cmorewood avatar image
cmorewood answered ·

ill go throught the settings again. thanks

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nickdb avatar image nickdb ♦♦ commented ·
The system tends to honour the lower of a group of settings. It is best practice to configure the charger properly before using ESS and DVCC to coordinate.


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cmorewood avatar image
cmorewood answered ·

Just to finish this thread off. It turns out that it was a bad VE cable. I swapped it with another MPPT and immediately started to give errors. New cable ordered.

Thanks

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Related Resources

MultiPlus-II Product page 

MultiPlus-II Manual

Multiplus-II GX Online Manual

MultiPlus-II 230V Datasheet 

VE.Bus Error codes

Additional resources still need to be added for this topic