Can Prismatic Cells Be Fully Automatically Graded?

As the industry has moved towards a demand for greater efficiency in battery manufacture and testing, battery sorting has evolved considerably. Much beloved by manufacturers building battery packs for electric vehicles (EVs), energy storage systems and other high power applications, prismatic cells are perhaps the most pressing question in the industry: can they be fully automatically graded? In this article, we’ll look at the technicalities and consider how the job might be done.
What is Prismatic Cell Grading?
Prismatic cell grading is the process whereby batteries are sorted according to metrics which predict battery performance such as capacity, voltage and internal resistance along with other factors such as internal resistance and quality. This is an important step to ensure that any cell will function throughout its life optimally and safely – battery packs filled with inconsistent cells enjoy reduced efficiency and lifespan, much less safety as packs for use in EV and energy storage systems. In simpler days where cells could be tested manually one at a time this sorting step was relatively unimportant, but as automatic sorting machines arrived the increased speed such machines bring has made the need for sorting words far more relevant.
The Technological Landscape of Automatic Cell Grading
Automatic grading and sorting of prismatic cells relies on a combination of sensors, sorting machines and turbines. Battery sorting machines apply awkward combination of tools, including infrared (IR) tests, impedance measurement and voltage tracking.These machines grade an incoming stream of cells, checking several at a time, and grading faster while staying correct.
The newest of these machines grade prismatic cells depending on:
Capacity: here the battery producers will be interested in maximum energy storage and what range they can expect from the machines they power.
Internal Resistance: in battery terminology, all about the promised life span of the cell, and reliability in the long term.
Voltage: the consequences of the cell being out of spec or not.
Impedance: basically a measure of resistance, and indicating the standard of battery.
Can our prismatic cells be graded fully automatically?
As is often the situation in respect of fully automatic battery sorting, much of the up to date on automatic machines stems from machines already in volume production.
But just how far can we extend grade packing as an autonomous dare?
The grading of the prismatic cell is well within the realm of the doable, but bringing it into the fully automatic stem brings a number of considerations:
Cell Variability: All these prismatic cells, you wouldn’t expect them to be exactly identical, but they should be by the same maker. The whole problem of the sorting machine monitoring cells all being essentially the same design colours the precise design of the machine. Some of the dissimilar cells have minor defects and other nonconformities that do not disqualify them from being used, but make special testing compulsory, and consequently automatic battery sorting is that little bit more complex. Newer machines should be able to grade an ‘acceptable’ percentage of cells from many different companies, and by using suitably adaptive algorithms without intervention is capable of the necessary results.
Testing Technology: It goes without saying that most modern battery testing is effected via the computer.“Random access grading machines with IR testers, impedance analyzers, and automatic visual inspection sorting machines can test and sort cells individually.”
“Conveyor systems: Some prismatic cell sorting systems are augmented with conveyors that move cells gradually to their test points. However, integrating this makes these systems imposing.”
“Software integration: Some fully automated systems have sophisticated software that controls the sorting function itself, keeping track of the parameters of each test done. This helps guarantee that the grading is consistent across all of the cells that it tests, and some of them can store some data about cells for quality measure and adjust their grading based on this.”
“Speed and throughput: Of course, a fully automated approach allows sorting through hundreds or thousands of cells per hour at a speed that humans simply can’t keep up with. Manufacturers of electric vehicles and battery pack suppliers would therefore be very interested in this and support its demand.”
Challenges and Limitations
While automatically grading prismatic cells might seem interesting, it’s definitely not without challenges that come with it:
“Initial cost: It might be quite exorbitant having testing machines put in place for grading requirements as well as overall testing and sifting of the cells. Only the bigger manufacturers would be able to afford it at the offset. Joint ventures will ease the burden of cost.”
“Calibration and maintenance: Constantly ensuring the automated equipment works no less than perfectly o, of course, requires companies investing to constantly calibrate them and this comes at a cost as well.”
“Defect detection: Some defects that have performance implications may only be detectable by manual inspection.”
Conclusion
Grading prismatic cells automatically isn’t only possible but will be brought to life in large-scale quantities with the help of other sorting machines, infrared testers, and efficiency-boosting sorting software with a subsequent high degree of accuracy to good effect. This more often ultimately means a more consistent product, and less human error. The initial big cost and extent of calibration and maintenance, however, might still be a stumbling block for manufacturers wanting to use such systems.