In the case of low temperature, when the battery temperature is lower than 0 ° C, the battery pack without heating function, after discharging the battery temperature is higher than 0 ° C, please charge immediately, or put the battery into the warm storage, until the battery temperature rises to more than 5 ° C and then charge. If it is a battery pack with heating function, please pay attention to whether the charger works when charging. After full charge, please disconnect the charger as soon as possible, and do not ignore it for a long time after full charge.
1. Heat the battery pack
If you do not consider the battery pack heating, it is basically impossible to do not lose capacity, after all, the temperature is -25 degrees environment; Such a low temperature environment, even if it is a simple room temperature charging, low temperature discharge will have a loss of battery capacity.
Suggestion: Heat the battery pack.
At present, our company‘s single battery (30Ah) can only ensure that it can be charged and discharged at 0 ° C without causing battery loss. If the module needs to be charged and discharged at -25 ° C, external heating is recommended. In addition, it has little to do with voltage, as long as there is lithium embedded in the negative electrode, it is possible to produce lithium.
2, reduce the charging speed
At -20 ° C, if the speed of C/30 is used to charge the ternary lithium battery, the final capacity is only 77% of the nominal capacity, if the charging speed is reduced to C/100, the final capacity can reach 100%, but it can be filled with a battery for 4 consecutive days. Therefore, you can consider slow charging to increase the battery temperature, and then change to fast charging, some car companies also have the function of BMS, such as C/5 speed to 20%, and then full speed charging.
3. Increase the battery temperature
Charging in the room as much as possible, such as the underground parking lot, some of the thermal management system is a good car company, absolutely can greatly improve the cold winter electric car battery life.
