I noticed a weird behaviour in my 3 phase system - 3x Multiplus, 6x Pylontech US3000C, Cerbo. with hybrid setup with grid connection - grid feed in is turned off with grid feed target 0. It's very obvious during night time, where there very little load.
What happens is that few times within an hour, there's occasinal charge going to battery from the grid. It's not much, couple hundreds of W there and there. Battery at that time was around 65%. I log data from TCP Modbus every 5s to my app where I have some charts, I double checked CSV file from VRM portal.
I put screenshots into a single file. Charts are from one hour logging during night. From top: Battery Power (W), L1, L2, L3., down at the bottom are values from VRM CSV file, you can see the load is quite low and constant, but the system works on battery and then from time to time it just acts weird.
Can someone please explain that or give me suggestings how to prevent this?