Why do 18650 Cells Need to Be Sorted Before Making Packs?

18650 cells are used in electric vehicles (EVs) and in many consumer electronics. These are desirable because of their great energy density and efficiency. However before these cells are able to be connected together to form battery packs, they must first be sorted… But why must such a simple thing be done?
Battery Pack Balance
The main reason for sorting 18650 cells is so that all the cells in a battery pack are similar in performance. Not all lithium-ion cells are the same, even from the same manufacturer and even if taken from a single batch. Variation in capacity, voltage, resistance etc. means that if cells of different characteristics are connected together, the cells will charge and discharge at different rates, adversely affecting the performance of the whole battery pack in the process.
Battery Pack Maximizing
Even if 18650 cells are merely of a different voltage in the same manufacturer batch, then putting them in a pack will surely lead to some cells being overcharged and others being deeply discharged. With time, the composer cells will degrade, and the battery pack will suffer as a whole. Sorting the cells means matching cells of similar voltage level together, and so they can all be charged and discharged together.3. Enhancing Safety
Safety is yet another critical area where sorting comes in. Cells in a pack can be mismatched such that they lead to risk of overheating, short circuits and even thermal runaway! A high resistance cell in a pack can cause the rest of the pack to overheat, thus increasing fire and explosion risk. By sorting the cells before application in packs, a danger of this nature can be easily avoided.
4. Improving Energy Efficiency
Battery packs using sorted 18650s are better energy efficient. When sorted properly, the 18650 cells have closely related reference regarding capacity and voltage which promotes the overall efficiency of the battery pack. This directly results in better energy storage and enhancement especially for car batteries as the need for longer battery life is critical for the car’s overall performance.
5. Following Industry Guidelines
Today, battery manufacturing requires strict adherence to laid down standards for the purpose of product quality. The sorting of the 18650 cells is another important step for terms of meeting such standards especially for packs meant for use in vehicles and industrial machines. This is important to avoid expensive recalls after notices from the regulatory bodies.
6. Machines That Do the Sorting
Hardly possible! Where battery sorting has to take place, there are machines meant to do it. With precision, such sorting machines measure the voltage, capacity and resistance of the cells and place them into different groups. Today, using the right battery testing machine and battery sorting machine is not only considered the most efficient but also the ideal for automating the process with minimal human labour.
Machines such as the 18650 battery sorting machine, prismatic cell sorting machine and lithium battery sorting machines are meant for this work. The automation makes selecting the proper cells for the battery pack fast and less prone to error.
Conclusion
As you can see, it goes without saying that sorting 18650 cells before application in battery packs is important for quality, performance of the pack as well as longevity. With sorting done using the right equipment such as sorting equipment or battery testing equipment, manufacturers can mitigate cell mismatching, use the pack to its maximum potential and also meet industry standards. Be you a member or newcomer in this cluster, Electric vehicles market, smart phones, circular, portable cameras and devices and all following electronics that depend on lithium the importance of knowing about sorting 18650 cells is bound to increase as new technologies continue creeping in.