What problems will occur if inconsistent batteries are used in series and used together?

1. Capacity loss. The battery pack is composed of single cells, and the capacity is in accordance with the barrel principle. The capacity of the worst cell determines the capacity of the entire battery pack. In order to guard against overcharge and overdischarge of the battery, the logic of the battery management system is set as follows: when discharging, when the lowest cell voltage reaches the discharge cut-off voltage, the entire battery pack stops discharging; when charging, when the highest cell voltage touches the charge cut-off voltage To stop charging. Take two batteries in series as an example. One battery has a capacity of 1C, and the other has a capacity of only 0.9C. In a series connection, two batteries pass the same amount of current. When charging, the battery with a small capacity must overflow first, and the charging cut-off condition is reached, and the system will not continue to charge. When discharging, a battery with a small capacity will inevitably emit all available energy first, and the system will stop discharging immediately. In this way, batteries with small capacity are always overflowing, while batteries with large capacity always use part of the capacity. Part of the capacity of the entire battery pack is always in an idle state 2. Life loss. Similarly, the life of the battery pack is determined by the cell with the shortest lifespan. It is very likely that the cell with the shortest life span is the cell with a small capacity. Small-capacity batteries are overflowing every time, and the output is too strong, which is likely to reach the focus of life first. When the battery cell's life ends all the time, a group of battery cells welded together will die. 3. The internal resistance increases. Different internal resistances flow through the same current, and a cell with a large internal resistance generates more heat. The battery temperature is too high, causing the deterioration rate to accelerate, and the internal resistance will further increase. Internal resistance and temperature rise form a pair of negative feedback, which accelerates the deterioration of high internal resistance cells. 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: What are the factors that affect the service life of ternary lithium batteries?