Hi
I am trying to set up a self consumption system, with the PV being the only thing to charge the batteries. However last night the battery got down to 14% and the Grid took over the load as expected but it also started charging the batteries at full charge rate (50Amps) drawing 4kw from the grid(my max 20amp setting in the multi for the grid connection) at a SOC of 20% I shut the AC off. I though it ight try to raise the battery to 16% due to battery life or some other battery preserve setting, so I let it run for a bit.
Setup: Multiplus2, A Fronius Primo 4500w on AC out, Cerbo GX. At present I only have one 5kw pylontech battery hooked up through can bus as I am trying to get this functionality to work, and my wifes car takes about 7kw after a trip to work and back. During this testing this is the only load on the system.
This morning with the PV charging the battery I turned back on the AC grid and soon after it returned to full charge rates on the battery again, with zero load on the output, PV was about 500wats at that time.
I have ESS turned on, min soc is 15%, No feed in to grid is allowed, all internal metering, M2 on the VE bus, battery on the Can bus to the Cerbo, Fronios via cat5e network.
I am sure I have missed a setting some where but I cant seem to find it. I have tried both "with battery life" and "without" and this is not changing the AC recharging the battery.
How do I stop the M2 from charging the battery from the Grid?
My Anticipated system setup is:
Self consume all PV power produced during the day time and at night for the entire home(minus the EV which is on a grid timed circuit), when the battery reaches min SOC set point, grid powers all loads until such times the PV is able to take over and supply loads and battery charging. Night time base load in the quiet hours is aprox 600w, peak in the morning is around 1.5kw, and around 2kw during the evenings. I have calculated provided we have a nice sunny day the 20kw battery should be sufficient as a starter to get through the 16hours of insufficient PV. I may need to increase the PV array but it will be via MPPT not AC coupled. This was a retro fit to existing so it made sense to keep the AC coupled.