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BMS AP9921X-AP9922; alarms “Charge Current Deviation”

 
 
 
Issue:
BMS AP9921X-AP922; alarms “Charge Current Deviation”

 
Product line:
Battery Management System (BMS) AP9921X & AP9922

 
Environment:
All models, all serial numbers

 
Cause:
When the Battery Management System applied a test current, the batteries listed in the alarm message showed a higher than acceptable percentage of deviation from the benchmarked values. (Benchmark values are set at installation, after a system reset, or after any discharge.) NOTE: The charge test detects changes within a battery and its inter-cell connectors.

 
Resolution:
Identify the listed batteries immediately so that system backup time is not reduced. Check for exterior causes of this alarm, such as a loose connection or corrosion on a battery post. If the battery has no external problems, perform a follow-up reading with a battery tester. If a specific battery causes repeated alarms (especially if the alarms have increasing deviation percentages), the battery is failing. Replace the battery. If random batteries occasionally generate Charge Test alarms, the Charge Current Deviation from Benchmark setting may be too close to the normal deviation range of the battery string. To reconfigure this value, see Charge Current Deviation from Benchmark.
 
Benchmark values are set at installation, after a system reset, or after any discharge.
 
 
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