Issue:
BMS AP9921X-AP9922; alarms “Battery Cell Shorted”
Product line:
Battery Management System (BMS) AP9921X-AP9922
Environment:
All models, all serial numbers
Cause:
The sum voltage of the indicated battery is below normal, usually by more than the voltage of one cell. The alarm value is calculated using the following formula: ((#Cells/Batt)-1) x (Vstring) (#Cells/Batt) x (#Batt/String) Example: A normally float-charged 12-V VRLA battery measures 13.5 V at 2.25 Volts per Cell (VPC). If the voltage falls below 11.25 V (2.25 VPC x 5 cells), but is still above 0.5 V, the battery activates the Battery Cell Shorted alarm.
Resolution:
Check the voltage reading of the indicated battery. If the alarm is accurate, replace the battery immediately.
Released for:Schneider Electric Global
