My system (Multiplus II GX, 48V with pylontech US3000c) was running 1 year wo problems. After I changed battery type from LiFePo4 to Pb-acid and back to LiFePo4 I got low battery alarm. Since that moment there was no ESS relais test done anymore. I loaded the battery up to 50V and more (by direct charge) but still "low battery" alarm.
The Switch is on "I". I did many resets (AC off / Switch Off - also pos. "II" tried) but no change / no reaction of "ESS relay test" (no clicking of relais on Switch or power ON). Communication to battery is via CAN-Bus, it works fine and BMS has no alarms or failure.
Any Help available? Thanks!