Knowledge

The lithium battery market offers a wide variety of quality grades. How can we distinguish between different quality levels?

• Battery cell quality classification
• How to judge battery cell quality

Battery Cell Quality Classification

Battery cells are commonly categorized as Grade A, Grade B, Grade C, etc.
This is the market quality classification, but we have never received such statements from battery cell manufacturers.

We provide a method for determining the quality of EVE prismatic cells.

How to judge battery cell quality

Internal Resistance Testing

The EVE datasheet specifies the internal resistance range for cells. Cells within this range are considered qualified.

For DIY batteries, EVE distributors often provide their customers with pre-welded studs (aftermarket) for easy assembly. Two common types are single M6 and double hole.

Because of the welded studs, testing the bolts will increase the internal resistance because the resistance includes the bolts. The correct method is to test other locations on the electrodes to determine the original battery cell internal resistance. (Theoretically, internal resistance is also affected by the battery cell charge level, testing equipment, humidity, and other factors.)

Battery Cell Flatness

We can find a level surface, lay the battery cell flat, and use a ruler to test its flatness. Alternatively, we can place two cells side by side. Grade A cells will ensure a good fit.

QR Code

The QR code uniquely identifies the battery cell, similar to a human ID card. The serial number on the QR code represents various meanings, including production date, production location, and manufacturer.

Some QR codes on the market have been polished and then re-laser-engraved. How can we determine if they are genuine QR codes?

We can remove the insulating tape on the top of the Prismatic cell to inspect for solder marks on the QR code.

If you have any other questions, please contact us.