Common faults of power batteries and related maintenance procedures Power battery knowledge

Power battery is one of the core components of electric vehicles, affecting the vehicle's performance, range, safety and reliability. It uses chemical reactions to store and release electric energy, through the charge and discharge process to provide power for electric vehicles. 

Performance parameters of power batteries include energy density, power density, cycle life, charging rate, etc., and the influencing factors include battery chemical type, battery design and manufacturing, cycle depth, etc.

Fault diagnosis and maintenance is the key to ensure the normal operation of power battery system. Fault diagnosis involves reading fault code, sensor inspection, battery balancing, temperature monitoring, etc., to determine the cause of the problem. Maintenance methods include module replacement, monomer replacement, maintenance, cooling system maintenance, etc., need professional technology and equipment. 

Common faults can be roughly divided into core temperature too high/too low fault, battery overcurrent discharge fault, battery internal resistance increase fault, core pressure difference too large fault, core voltage too high/too low fault, insulation fault, etc. 

I. Insulation fault 

Fault range: 

1, battery manager; 

2, battery; 

3, high-voltage wiring harness; 

Treatment process: 

1, use the megohm meter to check the insulation state of the power battery; 

2, disconnect the battery manager, measure the locking fault range respectively; 

3, after excluding the insulation fault, clear the fault code; 

II．The internal resistance of the battery increases

Fault range: 1, Battery manager; 2, battery core; 

Treatment process: 

1, Through the diagnostic tool to query the abnormal information;

2, Replace the battery manager; 

3, Repair or replace the corresponding high-voltage connection copper row;

4, Replace the battery core;

III. The pressure difference of the battery core is too large 

Fault range: 1, Battery manager; 2, high-voltage connection copper row; 3, collection wiring harness; 4, battery core; 

Treatment process: 

1, Read the diagnostic information; 

2, Check the high-voltage connection copper row bolt of the battery core; 

3, Replace the battery manager; 

4, Replace the battery core; 

IV. The battery overcurrent discharge 

Fault range: 1, Battery manager;2, current sensor;3, high-voltage wiring harness; 

Treatment process: 

1, Check the power battery assembly maintenance switch fuse;

2, Check the battery controller;

3, Check whether the high-voltage wiring harness is short-circuited;

4, Check whether the battery assembly is short-circuited; 

V. The battery core voltage is too high 

Fault range: 1, Battery manager;2, VCU;3, battery core;4, poor connection or wiring harness; Treatment process: 

1, Through the diagnostic instrument to query the number of abnormal battery core; 

2, Replace the VCU; 

3, Replace the abnormal core; 

VI. The core voltage is too low 

Fault range: 1, Battery manager; 2, the core; 

Treatment process: 

1, Through the diagnostic instrument to check the number of abnormal core;

2, Replace the VCU; 

3, Replace the abnormal core; 

VII. The core temperature is too high 

Fault range: 1, Battery manager; 2, the core;3, fan; 4, temperature sensor; 5, drive motor; 6, VCU Treatment process: 

1, Exclude high temperature environment large current discharge; 

2, To provide a separate 12V power supply to the battery assembly, if the fan is running normally, replace the battery manager; 

3, If the fan is abnormal, check the fan related wiring harness and fan assembly; 

4, With the diagnostic instrument to locate the abnormal temperature sensor, and replace; 

VIII. The core temperature is too low

Fault range: 1, Temperature sensor;2, the ambient temperature is too low;

Treatment process: 

1, Exclude the ambient temperature is too low;

2, With the diagnostic instrument to locate the abnormal temperature sensor, and replace;