question

Hello and many thanks for the quick feedback. I switched off the grid, the Quattros started to provide power to the house from the batteries, and the production of solar power came to zero (while there is plenty of sunshine...). This is not what I had expected (I thought the Fronius would continue providing solar power to feed house loads, and that the Quattros would provide additional power from batteries if the houseloads > solar power?).

On the SOC with batterylife,I think I understand what you say and because my system does not yet charge batteries automatically, the SOC stays limited at 80% (the only way I have been able to charge the batteries so far is through scheduled charges, which batterylife probably does not take into account).

On the system frequency and voltage, please see below a few additional shots from the Cerbo Touch. If frequencies, voltages from other parts of the system are needed, kindly let me know (I counted 12 softwares on my system, so data is plenty!).

Thanks for your help.

What happens if you switch on exporting of excess AC coupled solar to grid? Does the power go to the grid or does it start to charge the batteries?

Hello Rick987,

for me it seems to be a misconfigured or misinstalled ESS System. I am using three Multiplus II / 48 5000 / 70 in a three phase System together with the Fonius Symo 8.2-3 same as yours. My system stays "online" without grid and the solar works too without any interruption. If your Symo is switching off while the grid is off, it misses the synchronisation. The most important thing is the installation of the Fronius at the output side of the Victron Inverters, this is the side where the "critical loads" are feeded, the side with the UPS function. Second thing is the frequency range in the ESS setup, third the Fronius should be in "microgrid mode". Steering the load management should be done using Modbus/Tcp.

Best regards!

Hello, many thanks for the various tips, great to know there are people out there to help!

Good news: I got the batteries to charge from the solar panels during the sunny hours. I am in optimized mode without batterylife, with a minimum SOC of 65%. The problem seems to have been the grid set point. It had been set to 0W, I increased it to 100W, and, miracle, the charging started... I certainly don't understand why, but it works. Now, when there is grid power, the system works as intended, with one problem left: by the morning, the batteries have discharged to the set minimum SOC at 65%. At that stage, the charging from the solar panels won't start at a significant level (i.e. beyond a few hundred watts), unless I increase a bit the minimum SOC setting to, say 70%. At that point, the charging immediately goes to the max (several thousand watts) the solar panels produce (minus the power consumed by the loads). Right after that, I can decrease again the minimum SOC to 65%, this will not pertubate the charging of the batteries which will go on. I know there must be a way for charging to be triggered automatically. All suggestions on what I should be doing are welcome...

Now, when there is a power outage, the Quattros feed the loads from the batteries, and the Fronius is on (for example, I can go through the Fronius menu), but there is no power coming from the solar panels during the sunny hours, to help the batteries feed the loads. I will continue my research along the lines suggested in your messages.

Many thanks again!