Any factory produces products with defective rates, which determines the vitality of a factory. In terms of technology, ingredients, etc., there is no big gap between the first, second and third-grade lithium-ion battery factories. However, for production technology and manufacturing process, big defective rates gap happens. For example, the defective rate of first-grade factory can achieve about 2%, while that of second and third-grade may be 5-10%. Because of it, the ranks are distinguished.

A-grade cells ：According to the capacity, internal resistance, discharge capacity, size and other details shown in the battery design, the cell factories produce out the cells. After testing, normal cells are called A-grade cells, that is, all aspects of the parameters have been within the range of technical requirements. Then the factories carry out the matching of capacity, internal resistance, voltage and etc. to ensure the consistency before delivery. And the price of A-grade cells is always relatively high.

B-grade cells: When the factories produce out the cells, there are some defects in the voltage, capacity, internal resistance, appearance and other aspects failing to meet the standard of A-grade products, but the gap in the performance is small. However, the price of B-grade cells is cheaper than that of A-grade, so sometimes many factories directly ship out B-grade cells.

C-grade cells: C-grade cells are also called defective cells, namely the voltage, capacity, internal resistance or appearance is far from the standard parameters. For some defective cells, there are only individual parameters not up to standard, and others are in line with. During charging, the defective soft pack cells produce undesirable situations such as expansion, leakage, micro short circuit, self-discharge and so on. The safety and durability of such cells is poor, and after the subsequent cycle of charge and discharge, the performance will be greatly decreased. Generally well-known manufacturers will not hit their own brand logo in such cells to affect the reputation. There are also some manufacturers do scrap treatment, cut off the pole ear of soft pack cells and forbid selling (but there are always some outflow), or require the system vendors to remove the trademark or respray code to sell.

As one of the 36 battery pack manufacturers authorized by Panasonic, our company promises that all the cells we use are with A-grade.