I have had a Multigrid 48V 3kVa working flawlessly in an ESS system with a BYD battery for about 12 months.
A couple of days ago there was a power outage that lasted for over 6 hours.
The system stayed up during that time. When the mains grid power came back. The system switched over from inverter mode to pass through mode and stopped the discharging of the battery.
Why might this be?