WHAT ARE GRADE-A, B & C LIFEPO4 CELLS? HOW TO judge THEM?
While battery manufacturers produce the same batch of batteries, they will be classified according to the discharge test performance of the batteries and divided into four categories: ABCD.
What is Grade-A Lithium Cell?
Grade A is the designation of the high quality standard of the battery. Its battery materials, technology, energy storage, stable charging and discharging, specifications, and constant temperature standards are all high-quality standards in the industry.
Grade A cells had been generally place orders directly from the factory where the cells are used to the cell manufacturer. Cell manufacturers arrange production according to the factory’s production capacity and technical capabilities. After a series of cell manufacturing processes, the cells are finally produced and delivered to customers. Before placing an order, battery manufacturers typically communicate parameters such as battery capacity, thickness, length, and width. Then the battery produced completely according to the standard of the order is called Grade-A cell.
However, due to the vigorous development of the new energy vehicle market, the supply of electric vehicle batteries is in short supply. At the same time, A-level batteries are generally dominated by new energy vehicles, and it is difficult to directly purchase A-level batteries from major manufacturers in the market.
What is Grade-B Lithium Cell?
There must be a defective rate for Any factory producing products. This defective rate determines the quality of a factory. In the lithium battery industry, purely from the perspective of technology and composition, there will not be a big gap between the first-line lithium battery factory and the third-line lithium battery factory. However, considering the production process, the defective rate of manufacturers varies greatly. First-tier manufacturers can reach about 2%, while second- and third-tier manufacturers may reach 5-10%. It is precisely because of this defect rate that Class B batteries are created.
B-grade cells only have slightly different capacity, or the length, width and thickness do not meet the order requirements, but the performance is not compromised, and the price is cheaper than A-grade cells. In addition, A-grade batteries are generally placed in the warehouse. If they are not shipped within 3-6 months, they are also called B-grade batteries. Of course, this is just a popular saying.
What is Grade-C Lithium Cell?
Grade C batteries are below average in every way and below the standards of Grade A and B batteries. Grade-C cells are very different from Grade-A cells in terms of energy storage, stable charge and discharge efficiency, battery materials, technology, and repeated charge and discharge.
If the Grade-B battery has been in the warehouse for more than 8 months and has not been shipped, it can be called a C-grade battery. Due to the long storage time of Grade-C cells, the performance begins to decline, self-discharge, dust, and water vapor age, so the most likely situation for Grade-C cells is to increase the packaging. The swelling of the battery sometimes occurs when charging, and sometimes when it leaks and short-circuits. C-grade batteries are generally only about 50%-60% of similar A-grade batteries, and the best can reach 70%. Grade C batteries are less safe. In addition, Grade-C batteries are not durable, and their performance will be greatly reduced after being charged many times.
How to judge the cells of different grades?
The easiest way to tell the difference between a grade A battery and a grade B battery is that the grade A battery has the original manufacturer’s test report. The data should include the internal resistance, voltage, capacity and product code (usually the same information as on the QR code) of each battery. Without these, 99% are probably Grade B batteries. Typically, some Grade-A batteries are salvaged from EV industrial, and these batteries are often considered Grade-B batteries, even tap “B” label before left the storage.
