I have PowerWall 3 batteries with 9kWp solar array and a Myenergi Zappi to charge the car.
My DNO has limited my export to grid at 5kW.
Now the sun has finally appeared, I’m at the point where I have an excess of solar kW above what the house needs + the 5kW export to Grid + the batteries are fully charged.
I would like to use zappi to put this solar excess into the car - otherwise I just lose the excess solar energy when the PowerWall clips the solar power.
If I put the zappi into ECO+ (and I remember to tell Octopus Go not to be smart), if zappi thinks I’m exporting to Grid, it just ramps up to the full 7kW charge rate irrespective of how much is actually going to grid. Worse, if the solar generation drops below 7kW, zappi carries on at 7kW and starts discharging the battery until it thinks there’s no longer any excess going to grid.
I have an automation that can raise the Reserve on the batteries to the current state of charge - so preventing zappi from discharging the batteries. Sadly this resulted in constant “hunting” - zappi charges the car, spots there’s no longer excess going to grid, stops charging the car, spots there’s excess going to grid, starts charging the car etc.
Is there any way to control this e.g. calculate the “excess” and set the zappi to only charge up to this excess?