Now (Dec 2023) not all EVE LF280K cells with orginal intact QR and official test report (Excel) are real Grade A cells, many of them are Grade A Minus (Grade A-) cells.

Distinguishing between Grade A and Grade A- cells is crucial for customers to make informed decisions. While both types of cells may possess intact QR codes and official test reports, there are notable differences between them.

Advantage of Grade A Cells:

Grade A cells represent the highest quality available. They exhibit exceptional cell consistency, ensuring reliable performance in battery assemblies. When constructing a 16S 51.2V battery with Grade A cells, you can expect it to charge up to 57V or higher. This remarkable consistency among the cells ensures optimal battery performance and longevity.

Disadvantage of Grade A- Cells:

On the other hand, Grade A- cells, while still of good quality, do not offer the same level of cell consistency as Grade A cells. When assembling a battery with Grade A- cells, you may encounter limitations in terms of charging capacity. Specifically, the battery may only be able to charge up to 54.4V when one cell voltage reaches 3.6V, triggering cell over-voltage protection. This discrepancy in charging capability indicates higher variations and lower consistency among the cells.

How to Distinguish:

Here are improved methods to distinguish between Grade A and Grade A- cells:

1. Verification of Official Test Report (Excel): When examining the official test report, pay attention to specific details. Grade A- cells may have a missing "OCV3 Time" column and a "Group" column in the format of 1, 2, 3 rather than 1-1, 1-2, 2-1. However, it's important to note that relying solely on the test report may not be entirely reliable, as it can be falsified or manipulated.

2. Charging Test without Top Balance or Active Balance: Upon receiving the cells, refrain from performing top balance or using active balance techniques. Instead, assemble a 51.2V battery and proceed with the charging process. Monitor the battery closely and observe its charging behavior. If the battery can only be charged to approximately 55V before one cell reaches 3.65V, it indicates that the cells are Grade A- cells, which have a similar quality to the previous B-marked cells. For Grade A cells, the voltage usually can be 57V above.

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A customer bought claimed Grade A cells from other sellers, can only be charged to 54.4V without balance, check details here: Post Link

While active balancer working, voltage difference is still high at 55V

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Battery built with Gobel Power Real Grade A cells, voltage usually is above 57V, get details here: Test Link

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By implementing these improved methods, customers can have a more accurate assessment of the cell quality and make informed decisions when selecting between Grade A and Grade A- cells.