question

aleksejs avatar image
aleksejs asked

CERBO Badly control MPPT charger to get power.

Hi.

I have Vicrtron MPPT + Cerbo + Multiplus II.

I see many-many times Cerbo is unable to get full solar power from MPPT.

Today I see great sun, small power. (picture1) 2365W

After just CERBO restart in 1 minute I see maximal power (picture2) 2912W = > +20%

And this is happen daily.

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Can I somehow to ask CERBO to work better?


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2 Answers
nickdb avatar image
nickdb answered ·

Not enough to go on here.

Tell us about your system and its settings, is it a managed Li battery? Are you using ESS? How is it configured? What about DVCC?

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aleksejs avatar image
aleksejs answered ·

I have ESS, I have no managed Li battery. Battery is fully charged:

(After reboot power stay at 2900) The problem is in Solar batteries voltage. Cerbo is trying to get much current, bat voltage dramatically decreases. It is visible at pic1 and pic2.

I do not understand how to control MPPT progress.

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nickdb avatar image nickdb ♦♦ commented ·

That is PV voltage, not battery.

You need to post more detail or no one can help.

Check your wiring and measure the battery voltages at the battery, inverter and mppt. Check they are the same.

Without a managed battery, something may have an off voltage reading that is being shared by the GX.

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aleksejs avatar image aleksejs nickdb ♦♦ commented ·

Voltages 91.8V and 143.4V - are solar battery voltages. I mean after Cerbo restart it could re-calculate the solar battery power witch is {solar U} * {possible solar I}

The point of restart:

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nickdb avatar image nickdb ♦♦ aleksejs commented ·
The PV charger window only displays the voltage from the solar panels. The battery voltage is not shown. PV voltage will vary as the mppt tracks and power requirements change.

The Cerbo can't ramp production down unless it is told by something to do that. If the mppt is reducing power when the GX is up then it is being provided with data (shared sensors) which disagrees with it's own data, or it's settings are different and being overridden by the GX.

Again, this is guessing as you are not sharing details about your site setup and configuration.

Check the settings on the mppt, check all the voltages and compare to what is being reported by the GX and devices.

Something is wrong either with your installation or how it is configured, none of which we can access via the internet or from what has been discussed already.


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JohnC avatar image JohnC ♦ nickdb ♦♦ commented ·
There's something wrong with that 91.8V. Might be tracking panels with two mpp peaks. What are these panels? Are they set up with multiple strings of different series lengths?

Don't worry about the Cerbo at this stage, something else is wrong..


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aleksejs avatar image aleksejs JohnC ♦ commented ·
I have 3 strings of panels at different angles but in one direction. It was not my choise to do this, but limitations of the roof. Strings connected in parallel. MPPT itself can get better point but cerbo unfortunately no
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aleksejs avatar image aleksejs JohnC ♦ commented ·
3 strings of 4 panels each. Each string all panels are similar (375W)
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aleksejs avatar image aleksejs nickdb ♦♦ commented ·

Sorry, but I'm good enough to understand where are battery voltage and solar voltage.

Sorry, I do not understand installation details I hide? I told I have MPPT + CERBO + 48V Battery + Multipluss II. ESS is ON. The problem not in rechargeable battery.

I made tests and switching off Cerbo results increase of output power. More - In case of something Is consuming energy - after Cerbo restart it should be the same leak, but it is not.

Monitoring Installation for many many days I realized - Cerbo is managing MPPT. MPPT itself is producing power better per 20% comparing to time controlled by CERBO.

CERBO trying to get maximum current from solar via MPPT, but in this way Solar voltage dramatically drops down as result Power = U * I and produced less.

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