If the cell manufacturer can deliver cells with a proven quality history of OCV within +/-0.02V then you will be able to assemble and charge these cells without gross balancing. However, you will need to consider a few things: 1. cell manufacture, formation, ageing end of line testing all have reporting and metrics 2. This is what you are probably trying to avoid as it can take hours or even days for the pack balancing to remove large SoC differences. An SoC difference of 10% on a 100Ah cell will take 100 hours to remove with a 100mA balancing. This is the approach used by the satellite industry and adopted by motorsport. The cells undergo a number of checks from visual inspection, capacity and internal resistance measurement. Prior to assembling the battery packs you can charge/discharge all of the cells to a defined voltage. This ensures all of the cells are matched in SoC prior to assembly. Similar to option 3, but using just OCV to group cells such that the initial SoC of the cells in a pack will not require gross balancing. This does.
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Why is grouping important for lithium-ion power battery packs?
The service life, safety, and capacity of lithium-ion power battery packs relies heavily on the consistency among battery cells. Grouping is an effective procedure to improve consistency by screening cells with similar performance and assembling them into an identical group.
Battery grouping can be achieved via clustering techniques based on characteristics like static capacity, internal resistance etc. The dynamic characteristics-based method considers the battery performance during the entire charging-discharging process and has become one of the most promising grouping method.
How does a lithium-ion battery grouping process work?
In a typical lithium-ion battery grouping process, the charging and discharging data are collected by formation cabinets and sent to host computers for temporary storage. Each host computer manages a formation cabinet group and controls the behaviors of all cabinets in the group.
Which sorting method is used for lithium ion batteries?
A comparative study of sorting methods for lithium-ion batteries A novel grouping method for lithium iron phosphate batteries based on a fractional joint Kalman filter and a new modified K-means clustering algorithm M.S.H. Lipu, M.A. Hannan, A. Hussain, M.M. Hoque, P.J. Ker, M.H.M. Saad, A. Ayob
What is battery grouping?
Essentially, battery grouping aims to categorize battery cells according to their diversities in various characteristics. These characteristics mainly comprise static capacity, voltage, internal resistance ( Li, 2014) and thermal behavior ( Fang et al., 2013 ). Battery grouping can be achieved via a similarity analysis of any characteristic above.
How does consistence of lithium-ion power battery affect the life of batteries?
J. Electrochem. En. Conv. Stor. May 2022, 19 (2): 021016 (12 pages) Consistence of lithium-ion power battery significantly affects the life and safety of battery modules and packs. To improve the consistence, battery grouping is employed, assembling batteries with similar electrochemical characteristics to make up modules and packs.