What is the effect of temperature on the lithium battery pack? When Baidu inquired about the working environment temperature of the lithium battery pack, Baidu gave the answer that the normal lithium battery pack operating temperature is -20 ° C -60 ° C, but generally lower than 0 ° C The performance of the lithium battery pack will decrease, and the discharge capacity will be reduced accordingly. Therefore, the lithium battery pack has a full operating temperature, which is usually 0-40 ° C. Some special environmental requirements require different lithium battery pack temperatures, some of which can even Operate normally in an environment of hundreds of degrees Celsius.
As can be seen from the above, the upper and lower limits of the working environment temperature of the lithium battery pack are higher, which can meet most of the ambient temperature requirements, but the temperature has an effect on the working efficiency of the lithium battery pack. For example, the temperature is too low to cause lithium. The battery pack capacitor drops faster, and the internal resistance also increases.
Lithium battery pack internal temperature change reason
For the lithium battery pack, the internal heat of the battery generates reaction heat, polarization heat and Joule heat. One of the main reasons for the increase in the temperature of the lithium battery pack is the temperature rise caused by the internal resistance of the battery. In addition, due to the dense pendulum of the heat generating battery body Put, the middle area is bound to have more heat accumulation, and the less edge area increases the temperature imbalance between the monomers in the lithium battery pack.
Effect of different temperatures on the performance of lithium battery packs
When the temperature drops from 18 °C to 0 °C, the internal resistance of the 150Ah lithium battery pack is doubled. Below 0 °C, the discharge capacity of the lithium battery pack decreases rapidly. When the temperature drops to -10 °C, the internal resistance of the lithium battery pack increases. double.
The heat rate of the lithium battery pack is different at different temperatures. This is because the internal chemical reaction of the battery is closely related to the temperature. The ambient temperature is low, and the lithium battery pack will generate more heat when it runs.
The working environment temperature of the lithium battery pack has a certain influence on the internal resistance, heat rate, discharge capacity, cycle life, and state consistency of the battery.
Temperature adjustment method
Internal adjustment
Place the temperature sensor in the most representative, temperature change range, especially at the highest temperature and lowest temperature, and the heat accumulation in the center of the lithium battery pack.
External adjustment
Cooling adjustment: At present, considering the complexity of the battery pack thermal management structure, most of them adopt a simple air-cooling method. In view of the uniformity of heat dissipation, the parallel ventilation method is mostly adopted.
Heating regulation: The simplest heating method is to add heating plate to the upper and lower sides of the lithium battery pack for heating. It is also to wrap the heating wire before and after each lithium battery pack or to heat the membrane around the lithium battery pack.
