The following collation of basic battery fault handling methods, for your reference.

First, the voltage class failure

1、High battery voltage: After fully charged and static, the voltage of single string or several strings of battery is obviously high, while other monomer is normal.

Failure causes: ① collection error; ② LMU equalization function is poor or invalid; ③ cell capacity is low, the voltage rises faster when charging.

Failure causes

Treatment: ① The voltage display value of single unit is higher than that of other single units, measure the actual voltage value of single unit for comparison, if the actual value is lower than the display value and higher than that of other single units, the actual voltage value is higher than that of other single units.

If the actual value is lower than the display value, and the voltage is the same as the other single unit, then take the actual value as the standard to calibrate the voltage of LMU single unit; if the measured value is consistent with the display value, then the voltage of LMU single unit will rise faster.

If the measured value is consistent with the displayed value, then manually discharge the single battery for equalization. ② Check whether the voltage sampling line is broken or falsely connected;

③ Replace LMU.

2、Low battery voltage: after full power static, the battery voltage is obviously low for single or several monoblocs, but normal for other monoblocs.

Failure causes: ① collection error; ② LMU equalization function is poor or invalid; ③ cell self-discharge rate is large; ④ cell capacity is low and voltage drops faster when discharging.

④ Low capacity of battery cell and fast voltage drop when discharging.

Treatment: ① The voltage display value of single unit is lower than the rest of single unit, measure the actual voltage value of single unit for comparison, if the actual value is higher than the display value and compared with other single unit, the voltage will be lower than the display value.

If the actual value is higher than the display value, and the voltage is the same as that of the other single unit, then take the actual value as the standard to calibrate the voltage of the LMU single unit; if the measured value matches the display value, then the voltage will drop faster when discharging.

If the measured value matches the displayed value, then manually charge and equalize the single battery. ② Check whether the voltage sampling line is broken or falsely connected;

③Replace the LMU; ④Replace the faulty battery pack.

3、Differential pressure: dynamic differential pressure/static differential pressure. When charging the single voltage quickly to the full cut-off voltage jumping gun; step on the throttle, the single

Voltage than other strings drop rapidly; step on the brake, the single voltage than other strings rise rapidly.

Failure causes: ① connecting the battery copper plate fastening nut loose; ② connection surface with dirt; ③ core self-discharge rate is large; ④ core welding connection copper plate welded open.

Core welding connection copper plate welding (resulting in the string of single low capacity); ⑤ individual single cell leakage.

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

Replace the battery pack.

4、Voltage jumps: When the vehicle is running or charging, the voltage of single unit jumps.

Failure causes: ① voltage acquisition line connection point loose; ② LUM failure.

Treatment: ① tighten the connection point; ② replace the LMU.

Temperature faults

1、Thermal management failure;

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

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

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

② cooling failure (fan); temperature higher than a certain value, the fan does not work.

Cause: ① fan relay or BMU failure; ② fan or relay power supply circuit is abnormal.

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

2、High temperature: one or several temperature points in the battery system are high, and the alarm threshold is reached during operation or charging.

Failure causes: ① temperature sensor failure; ② LMU failure; ③ electrical connection abnormal localized heat; ④ fan is not on, poor heat dissipation; ⑤ near the motor.

Poor heat dissipation; ⑤ close to the motor and other heat sources; ⑥ overcharging.

Processing method: ① Measure the resistance value of the temperature sensor and the display value for comparison, if the actual value is lower than the display value, and with other

If the actual value is lower than the display value, and the temperature value is the same as other temperature values, then the actual value as the standard for calibration of the LMU temperature value; ② fasten the electrical connection points, clear the connection points of foreign matter

Ensure the fan is turned on; ④ Increase the heat insulation material to isolate the heat source; ⑤ Suspend the operation to dissipate the heat; ⑥ Stop charging immediately; ⑦ Replace the LMU.

Stop charging immediately; ⑦ Replace the LMU.

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

Failure causes: ① temperature sensor failure; ② LMU failure; ③ local heating pad abnormal.

Treatment: ① Measure the resistance value of temperature sensor and compare with the display value, if the actual value is higher than the display value, and the temperature value is the same as other values, then the actual value will be taken as the actual value.

If the actual value is higher than the display value, and with other temperature values are the same, then the actual value as a standard for calibration of the LMU temperature value; ② check and repair the heating pad; ③ replace the LMU.

4、Temperature difference; refer to the high and low temperature investigation method. Difference in heat generation of electric core.

Third, charging failure

1, DC charging fault; GB/T27930-2015 Charging can not start, charging jump gun, charging end SOC does not reset.

Failure causes:

① battery failure (voltage, temperature, insulation and other abnormalities)

② BMU failure (charging module or charging CAN abnormality)

②BMU failure (charging module or charging CAN abnormality) ③Main negative, charging relay abnormality

③ Abnormalities in main negative and charging relay ④ Abnormalities in CC1 to ground resistance and CC2 to ground voltage

⑤ PE ground abnormality

Handling method:

① Rule out battery failure

② Repair/replace the failed parts

②Repair/replace the failed parts ③Intercept the charging telegram and analyze the cause of failure.

2、AC charging fault;

Failure causes:

① battery failure (voltage, temperature, insulation and other abnormalities)

② BMU failure (charging module or charging CAN abnormalities)

②BMU failure (charging module or charging CAN abnormality) ③Main negative, charging relay abnormality

Abnormal resistance of CC to ground, abnormal voltage of CP to ground.

⑤ PE ground abnormality

Handling method:

①Remove battery faults

② Repair/replace the failed parts

②Repair/replace the failed parts ③Intercept the charging message and analyze the cause of failure.

Insulation failure

Failure causes: water in the battery box or plug-in, liquid leakage of the battery cell, high humidity, insulation false alarms, other high-voltage parts of the vehicle (controller, compressor, etc.) insulation is not.

(controller, compressor, etc.) insulation, however.

Treatment: ① positive pole to ground, if there is voltage or insulation resistance value is less than the specified value, then the negative pole circuit leakage; negative pole to ground, if there is voltage or insulation resistance value is less than the specified value, then the negative pole circuit leakage; negative pole

If there is voltage or insulation resistance value less than the specified value, the positive circuit will be judged as leakage. According to the size of the leakage voltage divided by

single string voltage value at this time can be calculated leakage point, and then analyze and deal with according to different situations.

V. Communication Failure

LUM communication failure, BMU communication failure; the whole vehicle is one or several LMU information, or the whole vehicle has no BMS information.

Failure causes: ① LMU / BMU failure; ② LMU / BMU power supply circuit or communication line contact failure / failure; ③ signal interference.

Signal interference.

Treatment: ① replace LMU/BMU; ② check and repair the power supply circuit/communication line; ③ check the shielding and wire checking to find and eliminate the source of interference.

①Replace the LMU/BMU

SOC abnormality

1, inaccurate; charging power ÷ nominal capacity = charging SOC If “charging SOC” + “remaining SOC” is deviated from the actual display value, or according to SOC and OCU, it is not accurate.

If “SOC charged” + “SOC remaining” deviates from the actual displayed value, or if the actual power is not corresponding to SOC according to the correspondence between SOC and OCV, we consider SOC inaccurate.

No change;

Failure causes: ① communication abnormality (data missing); ② current abnormality (Hall and its input/output circuit); ③ BMU failure; ④ other battery alarms.

Failure; ④ other battery alarm.

Treatment: ① Make sure the data is complete; ② Repair/replace the failed parts; ③ Eliminate all battery alarms.

3、Decline fast;

Failure causes: ① abnormal communication cycle ② abnormal current (Hall forward current, feedback current is small); ③ single voltage bias, falling fast; ④ BMU fault; ④ other battery alarms.

Low voltage of single unit, falling fast; ④ BMU failure; ⑤ low temperature.

Treatment: ① update BMU program; ② repair/replace the failed parts;

4、Decline slowly;

Failure causes: ① abnormal communication cycle ② abnormal current (Hall forward current is small, feedback current is large) ③ BMU failure.

Treatment: ① update BMU program; ② repair / replacement of failed components.

5、Bouncing；Confirm whether the program version number is correct or not

VII. Abnormal current

Failure causes: ① Hall and its input/output circuit; ② Hall reverse installation; ③ DC charging if BMS demand voltage or current is 0, the charger presses the “0” button.

If the demand voltage or current of BMS is 0 during DC charging, the charger outputs according to the minimum output capacity.

Treatment: ① Update BMU program; ② Repair/replace the failed parts.