I am monitoring a 5 KVA MP2 system with 14 kWh SolarMD battery and one can observe up to 3 V difference between the BMS reported Voltage and the VE Bus Voltage as measured by the Multi . Wiring is 70mm2 cable. The question is does the MP base low voltage warnings and cuttoffs based on what voltage ? VE BUS , BMS or something else ? Same goes for overload. Seem to get spurious overload and low Voltage warnings. Firmware 5.02.
You can see from the warnings what device has sent it; usually is will come from the ve bus system. Cut off is the same in ESS, its own measurements, but the bms will also have sent its own DVL/DCL signals if you have the logger connected. For low DC shutdown use the recommended cut off voltages, but use percentage as well, the ve bus SOC synchronises to the bms SOC so can work alot better that way.
DVCC can affect the behaviour to some degree. (Hence the name)
Alot of the time the warning is because the contactor in the MD has disconnected, so technically the battery is still on and measured its own voltage but there is not connection to the cables since the contactor is open.
