DESS feeding to grid when SoC below DESS target SoC

I observed a very strange behavior today. 730W of constant PV power, 210W of constant AC load, Battery SoC 34%, but the Multiplus was charging the battery with only 260W while feeding 230W to the grid. Constantly.

Only when the SoC reached the DESS Target SoC of 35% it started to respect my grid setpoint of +10W and dumped the full excess PV power to the battery.

And as soon as SoC drops below these 35%, it’s feeding 230W back to grid again!!!


In the following plot, notice how at 12:30 the yellow grid power is getting more and more negative until SoC jumps to 35%:

And this is the DESS schedule:

It’s charging to 46% right now from grid+PV.

My system is configured to Green Mode, no trading, feeding back battery to grid is forbidden.

It’s a Multiplus-II GX 3000 with EM540 grid meter, CAN-BMS battery (2x Pytes Ebox 48100R-C, at the time of my observations 100A charge/discharge limits) , two PV microinverters, and Venus OS 3.54

Update: let’s see if this helps: [DESS HACK] Unexpected Bat2Grid and Solar-Feedin. (Green Mode) - #39 by dognose

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