Analysis of the safety configuration of lithium battery packs and the inconsistency sorting method of lithium battery packs

In order to ensure the safety of the lithium battery pack, reliable safety protection will be set up. 1. The temperature of the safety valve should rise beyond the normal range, the safety valve will automatically open to release the pressure, and the battery will completely fail to ensure safety. 2. The resistance of the thermistor increases sharply to prevent the temperature from rising further. 3. Once the fuse has an over-current risk, the circuit will be disconnected to guard against the occurrence of a vicious accident. The inconsistency of lithium battery packs and the inconsistent sorting method of single cells need to be considered from three aspects. Single battery sorting, thermal management after grouping, the battery management system provides equalization function when a small amount of inconsistency occurs; batteries of different batches are not used together; even if the battery cells of the same batch are inconsistent due to inconsistent parameters It must be screened; lithium battery packs must be divided into two categories: static sorting and dynamic sorting: 1. Static sorting, which is based on the open circuit voltage, internal resistance, capacity and other characteristic parameters of the battery cell, selects target parameters, and introduces statistical algorithms , Set the screening criteria, and finally divide the cells of the same batch into several groups. 2. Dynamic screening is based on the characteristics of the battery cell during the charging and discharging process. Some choose the constant current and constant voltage charging process, some choose the pulse shock charging and discharging process, and some compare their own charging and discharging curves. Relationship between. Combining dynamic and static sorting, static screening is used for preliminary grouping, and dynamic screening is carried out on this basis, so that more groups can be divided and screening accuracy is higher, but the cost will rise accordingly. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: About 18650 lithium battery and its advantages and disadvantages