I got a 5k MultiPlus II running with a set of 10kWh BYD LiFePo4 batteries (with their own BYD BMS) en two DC-connected MPPT's with a total PV-capacity of around 2400Wp and a Cerbo "running things"..
The Cerbo is updated to the latest firmware (automagically through the internet). The MultiPlus II is on firmware 2623470 and runs the ESS-assistant more or less with the default values of the German gridcode with internal NS protection.
The only thing I didn't let the assistant change, is the type of battery (because of the BYD-specific settings for Absorption and Float).
This time of year I have quite a surplus of PV-energy so I started experimenting with ESS (Optimized with BatteryLife).
For some reason the system is NOT feeding the surplus of PV back to the grid :-(
Only if I set the grid setpoint to a negative value, the system starts to feed back the PV to the grid at the height I set the negative grid setpoint to....
Otherwise, the BMS (I think) switches off the MPPT's so they don't deliver any PV anymore :-(
For some reason it does that when the BMS says (at VRM and in Remote Console) that the batteries are at 99% instead of 100%. I have no idea why it does that but this doesn't bother me too much ;-).
I set the minimum SOC (unless grid fails) at 95% otherwise apparently the system thinks it should feed the loads from the grid, even when there's still enough PV to do that and even enough to charge the batteries.
So not the actual surplus of PV energy is fed into the grid, but the value set with the negative grid setpoint...
So when there's a cloud before the sun and the batteries are still above the minimum SOC (unless grid fails) then the system feeds the grid from the batteries if the PV drops below the value set in the negative grid setpoint....
I probably have some setting "wrong" to get this result, but I can't seem to think of what could be wrong....
If someone has suggestions..... they are more then welcome.