Detailed explanation of the echelon utilization of power lithium-ion batteries

The characteristics of retired batteries for new energy vehicles: 1. Due to the differences in the individual use habits of new energy vehicle users and the differences in the regional use environment (temperature, etc.), the attenuation of each pallet power lithium-ion battery is different, even if it is from the same manufacturer The same batch of batteries; 2. Power lithium-ion batteries not only have a service life, but also have a calendar life. The service life of retired batteries will not be too long. Many batteries even die without disease and fail instantly; 3. Traceability of retired battery parameters Generally inferior, the service life of reuse (the number of charge and discharge) is difficult to assess accurately; 4. The price is cheap or even zero; 5. Because it is a retired battery, there is generally no warranty or a short warranty period (usually no more than two year). Preparatory work before the use of the retired battery ladder: 1. Determine the meaning of the battery system interface; 2. Perform 1-3 cycles of charge and discharge detection, and initially grasp the capacity and self-discharge data of each battery cell; 3. Solve the entire battery Short-board cells in the middle (replaced or short-circuited); 4. Perform equalization of the entire battery (active or passive); 5. Perform 1-3 cycles of charge and discharge detection again to obtain the real-time data of each cell, and confirm Reuse method. Some tips and suggestions in the process of echelon utilization of retired batteries for new energy vehicles: 1. Don't try to disassemble the battery pack to divide the capacity and resistance of the single cells, because the workload is huge; 2. In the same project, It is recommended to use retired batteries for the entire pallet (whole vehicle); 3. Regarding short-board batteries (invalid batteries such as excessive internal resistance, low capacity, etc.), if the number of internal short-board batteries in a string does not exceed 1.5%, local short-circuit methods are recommended Solution; 4. The charging and discharging rate should not exceed 0.5C and the smaller the better; 5. In order to improve the system reliability, consider increasing the system redundancy, depending on the battery condition (generally greater than 50%). 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 article: Analysis of charging principle and correct charging method of ternary lithium battery