Pure electric vehicle battery pack capacity decreases fault maintenance

(1) Phenomenon

During the use of pure electric vehicles, the phenomenon of short range of mileage occurred, showing insufficient battery capacity.

Insufficient battery capacity

(2) The reason

① The voltage of the single energy storage battery is inconsistent, the capacity difference is large, and the single battery is protected prematurely.
② The battery pack is in the late life and the capacity decreases.
③ Temperature protection in the battery pack.
④ There are high energy consumption loads in the peripheral circuit.
⑤ The battery (nickel -cadmium battery) has long -term shallow charging and shallow power, and the memory effect is existed.
⑥ The performance of the discharge platform is too low to reach the requirements and fail prematurely.
温 The temperature of the battery pack has a low environmental temperature.
⑧In the long -term use of the capacity of the battery pack, the attenuation is accelerated.

(3) Determination of the cause of the fault

① Determine whether the charging is normal, and whether the charging volume of each charging is low. Due to the low charging capacity, the discharge capacity is reduced, and the cause of the fault needs to be found from the charging aspect.
② Check the temperature record of the discharge environment. When the temperature is low, the discharge capacity will decrease significantly.
③ If the battery has been stored for a long time, first of all, it should be maintained in accordance with the maintenance system and then used.
④ During the application of the battery pack, the voltage, current, temperature, etc. of the battery pack through the BMS inspection, and observe the ending of the discharge at the end of the discharge (the single voltage, temperature, etc.) caused by the reasons. What is the reason for the analysis and judgment of the parameter.
⑤ For battery packs with memory effects, such as nickel -cadmium batteries, in accordance with the system instructions or maintenance manuals, regular maintenance, a small current is fully charged and discharged 2 to 3 times, which can eliminate the memory effect and restore the capacity of the battery pack.
⑥ In some cases, a high energy consumption load is added to the circuit, which will cause the battery pack to shorten the discharge time, such as the electric equipment (car light, etc.) without turning off the air conditioning parking. Used under the normal application capacity of the battery pack, the attenuation of the battery pack will be very fast, which is manifested as the increase in the internal resistance of the battery and the discharge voltage is low.
⑦ During the application process, if some monomer batteries have long -term charging and discharge, the battery will have an internal resistance and high capacity decrease. This is the case if the battery group is short -circuited in the battery pack. Each battery pack has a certain applicable voltage and current range. Long -term application is beyond its range, and rapid decay and significantly decreased battery capacity will occur.

(4) Failing treatment measures

In the automotive power power system, general single batteries fail, such as high intraternal resistance and leakage, etc. At this time, the battery performance has been seriously affected. It is recommended to replace the battery. Subsequent applications will be better than other batteries.

For the cause of the failure of external factors, if most of the internal resistance of the battery has significantly increased and the battery pack capacity is reduced, the life of the battery pack has reached the end period and there is no maintenance significance. It is recommended to replace the battery pack directly.

The voltage is inconsistent, but the voltage of each monomer is within the normal range. It is usually the difference between the battery self -discharge and inconsistency. Figure 449 shows the fault treatment process of low -capacity battery packs.

Low-capacity battery pack troubleshooting process