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pablosol2 avatar image
pablosol2 asked

Quattro with ESS won't start inverting with low loads

Hi all,

I have a Quattro 15kVA running with ESS assistant. AC-Coupling with two 6kW Huawei inverters and a 12kWh battery bank (will increase to 55kWh shortly).


I have found that when PV inverters do not supply as much energy as demanded at home, it starts getting it from the grid instead of the battery bank. This seems to happen when loads are under 500W aprox. If I increase loads, it would start inverting from the batteries which is what it is expected to do.

I have tried different Grid Setpoints from 100W to 10W and Grid Feed-in is activated for AC-Coupled PV but nothing changes. It happens both with BatteryLife on and off.


Another weird thing is that once it reaches the float state it would switch to "discharging / absortion" very frequently with small currents normally under 2A. Is this normal or should I change any parameter?


Thanks in advance

MultiPlus Quattro Inverter Charger
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Alexandra avatar image Alexandra ♦ commented ·

@pablosol2

In absorption the behaviour is normal, the system 'pulses' the battery, so not really giving it current. The cells should be balancing there.

Is the behaviour of the PV inverters happening when batteries are full?

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pablosol2 avatar image pablosol2 Alexandra ♦ commented ·
Thanks Alexandra, then there is no need to be concerned because of switching from absortion to float and discharge continuously. The PV inverters are normally producing much more power than what is needed, so I use to be feeding-in the grid when this happens.


At this moment I am dumping 2kW to the grid and the battery bank won't start the bulk phase. It displays "recharging" and is charging at only 2A (optimized without battery life), which is very annoying. I think that Victron should check their charging algorithms. How can I start the bulk stage?

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Alexandra avatar image Alexandra ♦ pablosol2 commented ·

The battery state can be separate from the system production state. Are they van connected. You want the pv to be in bulk but your batteries really to be in float. Or not be used- or are you feeding from them as well?

The recharging state is usually triggered when they have been discharged and below the set SOC point. How does the system know about or measure the PV inverters?

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pablosol2 avatar image pablosol2 Alexandra ♦ commented ·

This is the situation at this moment. It does not make any sense, There is no way, it won't start charging the batteries despite there is plenty of PV production and the minimum is at 60%


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Alexandra avatar image Alexandra ♦ pablosol2 commented ·

@pablosol2

If you switch off grid does it charge?

The Victron has no communication with the PV inverters.

Does the huawei respond to frequency shifting so the victron can control its output at least?

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pablosol2 avatar image pablosol2 Alexandra ♦ commented ·
Yes, the UPS feature works nicely: I disconnet from the grid and it starts supplying 230Vac automatically (I tested several times)


You are right, it seems that it has no connection with the PV inverters (Huawei Sun2000 3ktl). It does not seem to detect them, although I enter the correct IP in the remote console. I don't know why it does not detect them, anyway, for the last few days, Quattro would start charging soon in the morning when PV was available from these inverters.


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