INTRO: While it is clear that electric vehicles or EVs have taken over the road thanks to a climate conscious consumer who also seeks efficiency, it is also important to understand the operating power behind them. Lithium-ion batteries, with high energy density, run the EVs and the key is the grading of cells with A-category batteries working the best for electric vehicles. 

---

There are numerous checks and protocols that a Li-ion battery must pass in order to be classified as A category. 

A-grade cells are nearly 30 to 40% more expensive than B-grade cells. As a result, the majority of lithium-ion batteries imported into India are B-grade.

---

The automobile industry is undergoing a revolution, with electric vehicles (EV) now accounting for a sizeable proportion of the market. Consumers, previously sceptical of EVs, are now ditching ICE (Internal Combustion Engine)-powered vehicles for these electric variants.

Most of our electronic devices—laptops, cell phones, wireless headphones and more—are powered by lithium-ion (also known as Li-ion) batteries. There are numerous battery chemical compositions available in the market, but lithium-ion is the best among them. It charges quickly and also holds the charge for an extended period of time.

These batteries also have a very high energy density thus they can store a lot of energy in a small amount of space. The most common lithium-ion chemistries are Nickel Manganese Cobalt (NMC) and Lithium Iron Phosphate (LIP). This is the reason top automobile manufacturers such as Tesla, Volkswagen and Tata Motors use lithium-ion batteries.

The grading system for these batteries during manufacturing is a very strict process. There are numerous checks and protocols that a Li-ion battery must pass in order to be classified as A category. Less than 10% of all batteries manufactured fail to meet the expectations of an A-grade battery and are thus classified as B-grade. C-grade cells are the lowest quality in the market because they do not meet required specifications.

A-grade cells are nearly 30 to 40% more expensive than B-grade cells. As a result, the majority of lithium-ion batteries imported into India are B-grade. Both A and B grade cells have the same capacity and impedance when new. This encourages fresh businesses to use B-grade cells as they are less expensive and perform nearly as well in the early stages.  

When compared to A-grade cells, B-grade cells have a faster rate of capacity fade. The cycle life of a lithium-ion cell is defined as the number of charge-discharge cycles at 80% Depth of Discharge until the cell’s retention capacity reaches 80% of its original capacity. Due to sudden discharges, B-grade cells can’t be reused after the recycling process. 

Internal Resistance (or impedance) is inversely proportional to the cell’s performance. The faster the cells can charge and discharge, the higher the impedance. EV batteries have lower impedance than Energy Storage Grade cells because EVs require fast charging and high power discharge. As a result, B-grade cells are not recommended for use in an EV.