Why we need to choose Grade A LiFePO4 Battery Cell?
What is Grade A LiFePO4 Battery Cells?
Grade A cell is the name of the battery’s high-quality standard. Grade A LiFePO4 battery cells are within the range of technical parameters in all aspects of the parameters, the appearance is intact (no damage), no swelling, and no abnormal battery can be called grade A. Its battery materials, technology, energy storage, stable charge and discharge, specifications, and constant temperature standards are all industry high-quality standards.
Grade A LiFePO4 battery cell is generally to make the factory using the battery cell directly place an order to the battery cell factory. The battery cell factory arranges production according to the factory’s own production capacity and technical ability. After a series of battery cell manufacturing processes, the final product is delivered to the customer. Before placing an order, the battery production plant generally communicates battery capacity, thickness, length, width and other parameters.
Then the battery made completely according to the standard of the order is called grade A cell.
Grade A cells:
It is good quality cells, Passed all the test from factory. Because Different of standard, So grade A+ and Grade A- cells. Some grade A- cells are from grade A+ cells, As many grade A+ have stock for long time, then it is grade A-cells. But many factory will put those stock grade A+ cell into grade B cells group.
What is Grade B LiFePO4 Battery Cells?
The efficiency of the grade B cell is 80% of that of the grade A, and its battery materials, technology, energy storage, repeated charge and discharge, etc. are quite different from the grade A cell, especially the defective rate, the defective rate of a cell in the battery pack It will cause the energy storage of the entire battery pack, leading to instability such as charging and discharging.
Any factory produces products, there must be a defect rate. Then this defect rate determines the vitality of a factory. In the lithium battery industry, there will not be a big gap between the first-line lithium battery and the third-line lithium battery factory based on technology, ingredients, etc., but in the production process and manufacturing process, there will be The difference in defect rate is very large. First-tier manufacturers can achieve about 2%, while second-and third-tier manufacturers may achieve 5-10%. It is precisely because of this defective rate that a grade B battery is created.
In fact, there is only a slight gap in the capacity of the grade B battery, or the length and width do not meet the order specifications, but the performance is absolutely not discounted, but the price is cheaper than the grade A.
In addition, if a grade A cell is generally placed in a warehouse if it has not been shipped for 3-6 months, it is also called grade B. Of course, this is just a popular saying.
Grade B cells:
1.self-discharging is exceed (Risk)
2.Capacity is not enough as datasheet
3.Inner resistance is exceed
4.Size is exceed
5.Appearance is not good
6.Weight is exceed
7.Voltage and capacity can not in same level
8.Stock for too long time
What is Grade C LiFePO4 Battery Cells?
Grade C cells are 60% of Grade A and 40% of Grade B, which is lower than the standards of Grade A and B cells. The energy storage, stable charging and discharging efficiency, battery materials, technology, repeated charging and discharging of Grade C batteries are quite different from those of Grade A batteries.
To be precise, Grade B cells have been stored in the warehouse for more than 8 months. If they are still not shipped, they can be called Grade C. Grade C cells are due to the long storage time and the aging of self-discharge, dust and moisture, so Grade C batteries are most prone to swelling.
Grade C cells
1.self-discharging is exceed. Most factory named them grade C, and need destroy.
2.Not working cells
The problem is not all factory will have grade C level. The grade C level cells need be destroy. But many factory just have grade A and Grade B two level. And some. factory will have a standard for grade B cells and grade C cells in self-discharging rate.
The best way to know a cell is Grade A or Grade B is to check if the cell meets the manufacturers specifications.
Below is some important parameters info for you to distinguish the Grade A /Grade B/ Grade C cells
Each cell will be produced with an unique QR code as a proof of identity. Which make it more convenient to be recognized for the manufacturers when offering after-sale services. Grade B cells are categorized as unqualified ones, they usually do not offer warranty. Manufacturers will scrape off this QR code for distinguishing. So if you find a battery cell that with QR code concealed. Mostly it is Grade B cells. However, all Grade B cells will be covered with a new insulating sheet. So if there’ s no obvious signs of QR code outside, you’ Il need to tear off the insulating sheet.
Tips: It does not mean that cells come with QR Code are all Grade A cells.
Size & Weight :Compare the results listed on the data sheet.
Capacity: If the capacity is a little higher than data sheet, it is Grade A cells
Internal Resistance: Compare the results listed on the data sheet
Self-Discharging Rate: Compare the results listed on the data sheet