48v 10kwh energy storage solar system.Case introduction of common faults of lithium battery BMS

1. The entire system does not work after the system is powered on. The possible reasons are abnormal power supply, short circuit or open circuit in the wiring harness, and no DCDC voltage output. Troubleshooting: Check whether the external power supply to the management system is normal and whether it can reach the minimum operating voltage required by the management system. Check whether the external power supply has a current-limiting setting, resulting in insufficient power supply to the management system. You can adjust the external power supply to meet the requirements of the management system. Electricity requirements; check whether the wiring harness of the management system is short-circuited or open-circuited, and modify the wiring harness to make it work normally; if the external power supply and wiring harness are normal, check whether the DCDC in the management system that supplies power to the entire system has voltage output; If there is any abnormality, replace the bad DCDC module. 2. BMS cannot communicate with ECU. Possible reasons: BMU (main control module) is not working, CAN signal line is disconnected. Troubleshooting. Check whether the power supply of BMU 12V/24V is normal; check whether the pin of the CAN signal transmission line is withdrawn or the plug is not inserted; monitor the CAN port. Data, whether BMS or ECU data packets can be received. 3. The communication between BMS and ECU is unstable. Possible reasons are poor matching of the external CAN bus and too long bus branches. Troubleshooting: Check whether the bus matching resistance is correct; whether the matching position is correct and whether the branches are too long. 4. The internal communication of the BMS is unstable. The possible reasons are loose communication cable plugs, irregular CAN wiring, and duplicate BSU addresses. Troubleshooting: Check whether the wiring is loose; check whether the bus matching resistance is correct, whether the matching position is correct, whether the branch is too long; check whether the BSU address is repeated. 5. The insulation detection alarm may be caused by battery or driver leakage. , The insulation module detection line is connected incorrectly. Troubleshooting: Use the BDU display module to check the insulation detection data, check the battery bus voltage, and whether the negative bus-to-ground voltage is normal; use an insulation megger to measure the bus and driver-to-ground insulation resistance. 6. The main relay does not close after powering on. The possible reasons are that the load detection line is not connected, the precharge relay is open circuit, and the precharge resistor is open circuit. Troubleshooting: Use the BDU display module to check the bus voltage data, check the battery bus voltage, and whether the load bus voltage is normal; check whether the load bus voltage rises during the precharge process. 7. The data of the acquisition module is 0. The possible reasons are that the acquisition line of the acquisition module is disconnected or the acquisition module is damaged. Troubleshoot and re-plug the module wiring, measure the battery voltage at the acquisition line connector to see if it is normal, and measure the resistance at the temperature sensor line plug to see if it is normal. 8. The battery current data error may be caused by loose Hall signal line plug, damaged Hall sensor, or damaged acquisition module. Troubleshooting: Re-plug the current Hall sensor signal line; check whether the Hall sensor power supply is normal and whether the signal output is normal; replace the acquisition module. 9. Excessive battery temperature difference may be caused by loose cooling fan plug or failure of the cooling fan. Troubleshooting: Re-plug the fan plug; power the fan separately and check whether the fan is normal. 10. If the battery temperature is too high or too low, the cooling fan plug may be loose, the cooling fan may be faulty, or the temperature probe may be damaged. Troubleshooting: Re-plug the fan plug; power the fan separately and check whether the fan is normal; check whether the actual battery temperature is too high or too low; measure the internal resistance of the temperature probe. 11. The system reports an error after the relay operates. Possible reasons include disconnection of the auxiliary contact of the relay and adhesion of the relay contact. Troubleshooting: Re-plug and unplug the wiring harness; use a multimeter to measure whether the on-off status of the auxiliary contact is correct. 12. Failure to use the charger for charging. Possible reasons: Abnormal communication between the charger and BMS. Troubleshooting. 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. 13. No BMS data is displayed on the vehicle instrument. Possible reasons: Abnormal connection of the main control module harness. Troubleshooting. Check whether the main control module harness is connected completely, whether there is a normal low-voltage working voltage of the car, and whether the module is working normally. 14. Detection data of some battery boxes Possible reasons for loss: some connectors in the vehicle may have poor contact, or the BMS slave control module may not work properly. Troubleshooting, check the connector contact, or replace the BMS module;. 15. SOC abnormal phenomenon: SOC changes greatly during the system operation, or jumps repeatedly between several values; during the system charging and discharging process, SOC has a large deviation; SOC always displays a fixed value. Possible reasons: the current is not calibrated; the current sensor model does not match the host program; the battery has not been deeply charged or discharged for a long time; the data acquisition module collects jumps, causing the SOC to automatically calibrate; two conditions for SOC calibration: 1) overcharge protection is reached; 2 ) The average voltage reaches above xxV. The customer's battery has poor consistency and when overcharged, the second condition cannot be met. Check the remaining capacity and total capacity of the battery through the display; the current sensor is not connected correctly; troubleshooting: calibrate the current in the touch screen configuration page; change the host program or replace the current sensor; perform a deep charge and discharge of the battery; replace the data acquisition module, and The system SOC is manually calibrated, and it is recommended that customers perform deep charge and discharge once a week; modify the host program and adjust the xxV in the condition "average voltage reaches above xxV" according to the customer's actual situation. Set the correct total battery capacity and remaining capacity; connect the current sensor correctly so that it works properly..

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