question

Any input current limits set on the gx or inverters themselves?

No limits set.

I experimented with some DVCC settings. If I activate SVS - Shared voltage sense, the MPPT DC power goes directly down to about 50W. SCS - Shared current sense seems to have no impact to the behavior in my configuration.

Any ideas?

It seems to me that this thread from 2019 is describing the same issue: https://community.victronenergy.com/questions/22506/ess-ac-dc-coupled-feed-in-excess-solar-charger-pow.html

Best regards

Michael

It is a SEPLOS BMS and it does send parameters via the CAN bus.

If the battery is full, the CCL is send with 0A obviously. But this should be ignored by the MPPTs as DC feed-in is configured active and the MPPTs should provide 100% power.

@blackmarlin

I have the same problem.

https://community.victronenergy.com/questions/175803/mppts-switch-off-when-soc-is-getting-colose-to-100.html

This seems to be a problem that affects some people:

https://community.victronenergy.com/questions/175803/mppts-switch-off-when-soc-is-getting-colose-to-100.html

https://community.victronenergy.com/questions/22506/ess-ac-dc-coupled-feed-in-excess-solar-charger-pow.html

Does the voltage difference between the absorption voltage (55,2V in my case) and float voltage (54,4V in my case) of the battery limit the max. MPPT DC feed-in power?

Best regards

Michael

Yo probaría de poner la flotación del inversor mas bajo que la flotación del mppt, medio voltio por ejemplo.

What happens when you turn off the PV inverter? I notice on the second screenshot, the grid voltage is a bit higher on L1 and L3

you should turn ON, the visibility of the Multis:

at settings -> system setup -> battery measurements:

then the multis are shown in VRM like this:

this might help to see, what the multis are actually doing.

Also it would be good, if you can read Modbus.

At Register 791, ID100, you can see, if the MPPT is actually throttled or not. (maybe there is just lack of sun power?)

Register 791:

Status 0 = MPPT is OFF

Status 1 = MPPT is ON, running throttled

Status 2 = MPPT is ON, running without limits

@Vicens I tried to set the voltages higher in the MPPT configuration. But as I have enabled DVCC this has no effect. The charge voltage of the MPPT is set automatically 0.4V higher than the charge voltage configured in DVCC by the victron system. Probably this is exactly to allow grid feed in, but is not sufficient in my case.

MPPT

@Astrayan I can see no difference if the PV inverter is disabled.

@Pedaaa

Here you can see a screenshot where the sun is shining very bright. MPPT solar power should be around 1500W instead of 618W.

I checked the Modbus register 791 (but with ID238 for the MPPT) and as long as the battery is charging, the status is:
2 = MPPT is ON, running without limits
As soon as the battery is full, the status changes to:
1 = MPPT is ON, running throttled

Why could the MPPT be throttled in this situation?

Best regards

Michael

OK. The screenshots you have provided show a maximum of 84W going from PV Charger to Grid. What's the largest number you can contrive?

I have the same problem.

https://community.victronenergy.com/questions/161792/mppt-limit-charge-power-instead-of-exporting-to-gr.html

When SOC is close to 100% then MPPT limits powet instead to feeding to the grid. It started when i have connected Fronius PV. My workaround is limiting charge power when charging state switched to absorption. Limiting charge in ESS menu to 0W, then it works fine. You have to disable dvcc to limit charge power in ess menu;/ I have custom script for this but you can use node-red from Venus OS Large. Until I found a solution, I was losing about 20% of PV energy...

@Astrayan I don't understand what you mean with 84W to the grid?

The best I could see was about 200 Watts to the grid. If there would be no load in the house, all the production would be exportet to the grid (this image was taken as I was testing to disconnect the PV inverter).

It is not clear to me why the MPPT is throttled down when the battery is full. Tomorrow I will test if there will be any difference if I set the float voltage = charge voltage. Currently I have 54V float voltage and 55.2V charge voltage.

Best regards

Michael

I think the problem in my setup was that I had configured the same charge voltage 55,2V as DVCC maximum charge voltage and additionally in VE Configure as absorption voltage.

I changed it now in VE Configure to a higher value (57,6) and left it at 55,2V for DVCC maximum charge voltage. I am not 100% sure but this could have prevented the PV charger to raise the voltage to the automatically configured 0,4V offset which is necessary to export all the 2kW of power in my case.

Now I can see also higher PV power from PV charger Terrasse exported to the grid. But I don't see the float state of the working as expected. The battery is constantly charged / discharged with low current. This was not the case in the setup before.

Best regards

Michael

I think I have to correct my post. The improvment is not related to the offset but to the circumstance that I have reduced the DVCC maximum charge voltage which prevents the Seplos BMS from disabling the discharge switch (MOSFET).

Is there any relation? I thought this could be a way to reach float state (if the discharge MOSFET is opened), but in that case the MPPT is limited.

Can I see the value of the Modbus register 791 (MPPT is ON, running throttled) also in the VRM in the extended diagram section? Or with MQTT?

Did you have activated the Battery Monitor in den Multiplus configuration? If so, that might be the problem...

I have a similar problem.. why the battery monitor can be the problem ?

I my system there is no external battery managment or controlling - dvcc is off.

MPPT is charging the battery until it is nearly 100% SOC and then reduces the charging power to 0Watt. I have DC and AC coupled PV.

I just saw in the settings off mppt that the charge mode is "float" and my multiplus says "bulk".. maybe this i a sign that something is wrong.

Why my MPPT not feed to grid ? In settings this turned on.