Seven major faults and treatment methods for power batteries

First, the voltage class failure

1. The battery voltage is high: after the power is fully charged, the single or several strings of the battery are obviously high, and the other monomers are normal.

The cause of the fault: 1 acquisition error; 2LMU equalization function is poor or invalid; 3 cell capacity is low, the voltage rises faster when charging.

Treatment method: 1 the voltage display value of the monomer is higher than the other monomers, and the actual voltage value of the single cell is measured for comparison. If the actual value is lower than the displayed value and is the same as the voltage of other cells, the actual value is the standard for the LMU. The cell voltage is calibrated; if the measured value matches the displayed value, the cell is manually discharged and equalized. 2 Check whether the voltage sampling line is broken or not. 3 Replace the LMU.

2, the battery voltage is low: after the full power is static, the battery voltage of a single or a few cells is obviously low, and the other monomers are normal.

Fault reason: 1 acquisition error; 2LMU equalization function is poor or invalid; 3 cell self-discharge rate is large; 4 cell capacity is low, voltage drop is faster when discharging.

Treatment method: 1 the voltage display value of the monomer is lower than that of the other monomers, and the actual voltage value of the single cell is measured for comparison. If the actual value is higher than the display value and is the same as the voltage of other cells, the actual value is the standard for the LMU. The cell voltage is calibrated; if the measured value matches the displayed value, the cell is manually charged and equalized. 2 Check whether the voltage sampling line is broken, virtual connection; 3 replace the LMU; 4 replace the faulty battery pack.

3, pressure difference: dynamic pressure difference / static pressure difference. When charging, the single-cell voltage quickly jumps to the full-power cut-off voltage; when the throttle is stepped, the cell voltage drops rapidly compared with other strings; when the brake is applied, the cell voltage rises faster than other strings.

Fault reason: 1 connection battery bronze fastening nut loose; 2 connection surface has dirt; 3 battery core self-discharge rate; 4 battery core connection copper plate open welding (causing the string monomer capacity is low); 5 individual cells The core leaks.

Treatment method: 1 tighten the nut; 2 remove the foreign matter on the connection surface; 3 charge/discharge the single-string battery; 4 replace the problem battery pack.

4. Voltage jump: When the vehicle is running or charging, the single voltage jumps.

Fault reason: 1 the voltage collection line connection point is loose; 2LUM fault.

Treatment method: 1 fasten the connection point; 2 replace the LMU.

Second, the temperature class failure

1. Thermal management failure;

1 heating failure (heating sheet); when the temperature is lower than a certain value, heating does not turn on during charging.

Fault reason: 1 heating relay or BMU fault; 2 heater chip or relay power supply circuit is abnormal.

Treatment method: 1 repair or replace the heating relay or BMU; 2 check and repair the power supply circuit.

2 Thermal faults (fan); after the temperature is higher than a certain value, the fan is not working.

Fault reason: 1 fan relay or BMU fault; 2 fan or relay power supply circuit is abnormal.

Treatment method: 1 repair or replace the fan relay or BMU failure; 2 check to repair the power supply circuit is abnormal.

2. High temperature: One or a few temperature points in the battery system are high, and the alarm threshold is reached during operation or charging.

Fault reason: 1 temperature sensor failure; 2LMU fault; 3 electrical connection abnormal local heat; 4 fan is not turned on, heat dissipation is poor; 5 is close to the heat source such as motor; 6 overcharge.

Treatment method: 1 Measure the temperature sensor resistance value and display the value. If the actual value is lower than the displayed value and the same as other temperature values, the LMU temperature value is calibrated according to the actual value; 2 tightening the electrical connection point Clear the connection point foreign matter; 3 ensure that the fan is turned on; 4 increase the insulation material to isolate from the heat source; 5 suspend operation for heat dissipation; 6 immediately stop charging; 7 replace the LMU.

3. Low temperature: One or a few temperature points in the battery system are low, and the alarm threshold is reached during operation or charging.

The cause of the failure: 1 temperature sensor failure; 2LMU failure; 3 local heating sheet is abnormal.

Treatment method: 1 Measure the resistance value of the temperature sensor and compare it with the displayed value. If the actual value is higher than the displayed value and is the same as other temperature values, the LMU temperature value is calibrated according to the actual value; 2 check the repair heating piece; 3 replace the LMU.

4. Temperature difference; refer to high and low temperature troubleshooting method, cell heating difference.

Third, charging failure

1. DC charging failure; GB/T27930-2015 charging cannot be started, charging jump gun, SOC is not reset after charging.

Cause of issue:

1 Battery failure: (voltage, temperature, insulation, etc.)

2BMU failure (charging module or charging CAN abnormal)

3 main negative, charging relay is abnormal

4CC1 ground resistance, CC2 ground voltage abnormality

5PE abnormal

Approach:

1 troubleshoot the battery

2 repair / replacement of failed parts

3 Intercept the charging message to analyze the cause of the failure.

2. AC charging failure;

Cause of issue:

1 Battery failure: (abnormal voltage, temperature, insulation, etc.)

2 BMU fault (abnormal charging module or charging CAN)

3 Main negative, charging relay is abnormal

4 CC earth resistance, CP ground voltage abnormality

5 PE abnormal

Approach:

1 Troubleshoot the battery

2 Repair / replacement of failed parts

3 Intercept the charging message to analyze the cause of the failure.

The page contains the contents of the machine translation.