How to distinguish whether LiFePO₄ batteries purchased from China are Grade A or Grade B

According to the latest report released by the International Energy Agency in March 2025，Worldwide battery production now hits 3 terawatt-hours (TWh). Still, China leads the pack by a wide margin - making up more than three out of every four batteries made globally.

Lithium Iron Phosphate (LiFePO₄) batteries now play a big part in power storage and electric cars worldwide - especially over the last few years. Their growth comes from China's production strength; also, this battery type lasts longer, stays safer, and costs less to make.

For people working in the field - like buyers, suppliers, or installers - knowing if LiFePO₄ batteries from China are top quality or lower grade matters a lot when buying them. Instead of guessing, they check details closely. Some rely on test results, others look at performance history. Quality isn't always obvious just by looking. That’s why real-world data helps more than marketing claims. While some sellers promise high standards, proof comes from consistent output. So comparing actual specs makes a difference. Because even small flaws can cause big issues later on.

Understanding the Difference Between Grade A and Grade B LiFePO₄ Cells

Before you can tell Grade A apart from Grade B，let’s figure out what each grade actually means.

Definition of Grade A LiFePO₄ Cells

Grade A cells work exactly as ESS manufacturers say they should. Yet these units show zero dents or scratches. While their output stays strong across every batch. Because there’s no bulging anywhere on the outside.

Definition of Grade B LiFePO₄ Cells

Some B-grade cells fall short of top-tier quality. These units might show small flaws - or even bigger issues - like odd looks, higher resistance, or less power. Often, they’re leftovers from making high-end batteries. Rejected during checks, they didn’t pass strict tests.

On top of that, Grade A cells sitting unused in storage for 3 to 6 months might get loosely called Grade B. It’s less a hard rule, more like common talk among peer personnel.

To give you more ideas of differences, please see the below chart for checking.

LiFePO₄ Battery Comparison

Conclusion

You’ve got the full picture on spotting Chinese LiFePO₄ battery cells - whether they’re Grade A or Grade B. Use hands-on tests, check who’s supplying, look closely at build quality, while tracking where materials come from. One isn’t better than the other across the board; still, being able to tell the difference keeps you safe from scams, weak output, and potential hazards.

Frequently Asked Questions

Q: Are B-grade battery cells safe to use?

A: In the case of B-grade battery cells, they're completely safe for low-demand solar systems.

Q: Why is it important to verify battery data?

A: Sellers can manipulate A-grade QR codes, which is why it's really important to verify the data.

Q: Can end users access factory information by scanning the battery code?

A: Regular end users can't get factory information by scanning the battery code, all they get is a numeric code that can tell them what the brand is, when it was made and other information about the battery cells.

Q: What are reliable test methods for grading battery cells?

A: Well-known, reliable test methods for grading cells include a combination of internal resistance and capacity testing, which provide the most accurate classification.

Q: Do B-grade cells always come from defective ones?

A: And B-grade cells don’t necessarily come from defective cells, they can also be brand-new cells that didn't quite live up to the standards of A-grade.