Analysis of 12 common fault types of battery management system (BMS)-2

Battery Management System (BMS) is responsible for controlling Lead acid battery charging and discharging and estimating Maintenance Free Battery status. It is closely related to batteries and vehicle systems.

But in fact, among all the faults, compared with other systems, the fault of BMS is relatively high and difficult to deal with. Such a irresponsibility behavior has caused damage to the healthy development of the industry while planting security risks.

Therefore, a lithium TV big data reporter did a analysis, collated on BMS common fault type,for reference in the industry.

7. Excessive battery temperature difference

Possible reasons:

The cooling fan plug is loose, the cooling fan is faulty, the coolant fails, and the cold zone system does not start.

Troubleshooting method:

Reinsert the fan plug cable. Power on the fan separately, check whether the fan works properly, replace the coolant, and check the cooling system.

8. The system will report an error after relay operation

Possible reasons:

Relay auxiliary contact break line, relay contact adhesion

Troubleshooting method:

Re-plug the wiring harness; Use a multimeter to measure whether the on-off state of the auxiliary contact is correct, and replace the relay after the reason for the fault is removed.

9.You can't use a charger to charge

Possible reasons:

The communication between the charger and the BMS is abnormal

Troubleshooting method:

The communication between the charger and the BMS is abnormal. Replace a charger or BMS to confirm whether the BMS or the charger is faulty. Check whether the matching resistance of the BMS charging port is normal.

10. Vehicle instrument has no BMS data display

Possible reasons:

The cable harness of the main control module is improperly connected.

Troubleshooting method:

Check whether the wiring harness of the main control module is fully connected, whether there is the normal low-voltage working voltage of the car, and whether the module works normally.

11. Detection data of some battery boxes is lost

Possible reasons:

11. The detection data of some Maintenance Free Lead Acid Battery boxes is lost. Some plug-ins of the vehicle may be in poor contact, or the BMS slave control module cannot work normally

Troubleshooting method:

Check the contact condition of the connector, or replace the BMS module; .

12. SOC is abnormal

Symptom: SOC varies greatly during system operation, or jumps repeatedly between several values; During the charging and discharging process of the system, SOC has a large deviation. SOC always displays a fixed value.

Possible reasons:

Current is not calibrated; The current sensor model does not match the host program; The battery is not deeply charged and discharged for a long time; Data acquisition module acquisition jump, resulting in SOC automatic calibration; Hall sensor failure;

Two conditions for SOC calibration: 1) to achieve overcharge protection; 2) The average voltage reaches above xxV. Customer battery consistency is poor, overcharge, the second condition cannot be achieved. The remaining capacity and total capacity of the battery are displayed. The current sensor is not properly connected.

Troubleshooting method:

Calibrate the current in the touch screen configuration page; Change the host program or replace the current sensor;

A deep charge and discharge of the battery; Replace the data acquisition module, manually calibrate the SOC of the system, and recommend customers to conduct in-depth charge and discharge once a week; Modify the host program, according to the actual situation of the customer to adjust the average voltage to xxV above the condition of xxV. Set the correct total capacity and remaining capacity of the battery; Connect the current sensor correctly and make it work properly.

Conclusion:

It is reported that BMS is an indispensable component of power and energy Storage Battery packs. With the development of the new energy industry chain, the technology and market scale of BMS are growing at a high speed.

In terms of technology, Starting Point Research (SPIR) statistics show that in 2017, the cost of BMS accounted for 20% of the total battery pack cost on average. In 2018, after the rapid development of technology, it has been reduced to more than 15%, accounting for about 6% of the vehicle cost.

A management system manufacturers related personnel said that there were insulation detection alarm, collection module data is 0 and so on, now less.

Now, the rapid development of BMS technology, in insulation detection, has basically no alarm related problems; At the same time, it is very rare for the data of the acquisition module to be 0.

In terms of the market, Starting Research (SPIR) predicts that the compound average annual growth rate of the global BMS market brought by new energy vehicles will reach about 30 percent from 2018 to 2025.

Thus, the market development is uneven in good and bad, in addition to part of the phenomenon of good and unhealthy, BMS technology development and market size compared before, have a qualitative leap, and continuous progress.