Seven Common Faults of Power Battery and its Treatment

One, voltage failure

1.The battery voltage is high: After the battery is fully charged, thevoltage of the battery string or strings is obviously high, and othermonomers are normal.

Failure reasons: 1acquisition error; 2 LMU poor balance or failure; 3 battery capacity islow, the voltage rises faster when charging.

Processingmethod: 1 The unit voltage display value is higher than the rest of theunit, and the actual voltage value of the measurement unit is compared.If the actual value is lower than the displayed value and the voltageis the same as other units, the actual value is used as the standard forthe LMU. The cell voltage is calibrated; if themeasured value matches the displayed value, the cell is discharged andequalized manually. 2 Check whether the voltage sampling line is broken and make a virtual connection; 3 Replace the LMU.

2.The battery voltage is low: After the battery is fully charged, thevoltage of the battery alone or several cells is obviously low, andother monomers are normal.

Failurereasons: 1 collection error; 2 LMU poor balance function or failure; 3battery self-discharge rate; 4 battery capacity is low, the dischargevoltage drops faster.

Processingmethod: 1 The voltage display value of the single cell is lower thanthat of other monomers, and the actual voltage value of the measuringcell is compared. If the actual value is higher than the displayed valueand the voltage is the same as other cells, the actual value is used asthe standard for the LMU. Thesingle cell voltage is calibrated; if the measured value matches thedisplayed value, the cell is manually charged and balanced. 2 Check whether the voltage sampling line is broken or not. 3 Replace the LMU. 4 Replace the faulty battery pack.

3, pressure difference: dynamic pressure / static pressure difference. Whenthe battery is charged, the voltage of the cell rapidly jumps to thefull-power cut-off voltage. When the accelerator is pressed, the voltageof the cell drops faster than that of other strings. When the brake isapplied, the voltage of the cell rises faster than other strings.

Failurereasons: 1 connect the battery copper fastening nut loose; 2 connectionsurface dirt; 3 high self-discharge rate of the battery; 4 weldingwelding copper joints (causing the string of low capacity); Core leakage.

Treatmentmethods: 1 fasten the nut; 2 clear foreign objects on the connectionsurface; 3 balance the charge/discharge of the single string battery; 4replace the battery pack with the problem.

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

Cause of fault: 1 Loose connection point of voltage collection line; 2 LUM failure.

Treatment methods: 1 fasten the connection points; 2 replace the LMU.

Second, temperature failure

1, thermal management failure;

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

Failure reason: 1 heating relay or BMU failure; 2 heater or relay power supply circuit is abnormal.

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

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

Cause of the fault: 1 Fan relay or BMU is faulty; 2 Fan or relay power supply circuit is abnormal.

Treatment methods: 1 repair or replace the fan relay or BMU failure; 2 check repair power supply circuit anomalies.

2.High temperature: The temperature of one or more temperature points inthe battery system is high, and the alarm threshold is reached duringoperation or charging.

Failurecauses: 1 temperature sensor failure; 2LMU failure; 3 electricalconnection abnormal local heating; 4 fan is not turned on, poor heatdissipation; 5 close to the motor and other heat sources; 6 overcharge.

Processingmethod: 1 Measure the temperature sensor resistance value and thedisplayed value. If the actual value is lower than the displayed valueand it is the same as other temperature values, use the actual value asthe standard to calibrate the LMU temperature value. 2 Tighten theelectrical connection points. ,clear connection points foreign body; 3 to ensure that the fan isturned on; 4 increase the insulation material and heat source isolation;5 suspended operation to dissipate heat; 6 immediately stop charging; 7replace the LMU.

3.Low temperature: The temperature of one or more temperature points inthe battery system is low, and the alarm threshold is reached duringoperation or charging.

Failure causes: 1 temperature sensor failure; 2LMU failure; 3 local heater abnormalities.

Processingmethod: 1 measuring temperature sensor resistance value and displayvalue comparison, if the actual value is higher than the displayedvalue, and other temperature values are the same, then the actualvalue is calibrated to the LMU temperature value; 2 check the repair ofthe heating film; 3 Replace the LMU.

4, temperature difference; refer to high and low temperature troubleshooting methods. Battery core heat difference.