Unlocking the Secrets to Spotting Grade A LiFePO4 Cells

With the rapid development of renewable energy storage, countless manufacturers and suppliers of LiFePO4 batteries have emerged in China. However, the quality of these manufacturers varies significantly. So, how can you ensure that the home battery you purchase is made with Grade A LiFePO4 Cells?

In China, LiFePO4 cells are typically divided into five grades:

- GRADE A+
– GRADE A-
– GRADE B
– GRADE C
– SECOND-HAND

Both GRADE A+ and GRADE A- are considered Grade A LiFePO4 Cells. However, GRADE A- shows slightly lower performance in terms of total capacity, cell consistency, and internal resistance.

How to Quickly Identify Grade A LiFePO4 Cells?

If you are a solar equipment distributor or installer working with a new battery supplier, how can you quickly determine whether the supplier is providing you with Grade A LiFePO4 Cells? Follow these steps, and you’ll quickly gain this valuable skill.

Step 1: Assess the Energy Density of the Cells

Let’s start by comparing the energy density of 3.2V 100Ah LiFePO4 cells from the top five energy storage battery manufacturers in China:

TIPs: Energy Density = Capacity / Weight

From this data, we can conclude that Grade A LiFePO4 Cells from leading manufacturers have an energy density of at least 140Wh/kg. Typically, a 5kWh home battery requires 16 such cells, with the battery casing weighing around 15-20kg. Thus, the total weight would be:

 TIPs: Energy Density = Capacity / (Cell weight + Box weight)

In other words, a 5kWh home battery using Grade A LiFePO4 Cells should have an energy density of at least 90.90Wh/kg. According to the specifications of BSLBATT’s Li-PRO 5120 model, the energy density is 101.79Wh/kg, which aligns closely with the data for EVE and REPT cells.

Step 2: Evaluate the Weight of the Cells

Based on the data from the four leading manufacturers, the weight of a single 3.2V 100Ah Grade A LiFePO4 cell is approximately 2kg. From this, we can calculate:

- A 16S1P 51.2V 100Ah battery would weigh 32kg, plus a casing weight of around 20kg, for a total weight of 52kg.
- A 16S2P 51.2V 200Ah battery would weigh 64kg, plus a casing weight of around 30kg, for a total weight of 94kg.

(Many manufacturers now directly use 3.2V 200Ah cells for 51.2V 200Ah batteries, such as BSLBATT’s Li-PRO 10240. The calculation principle remains the same.)

Thus, when reviewing quotations, pay close attention to the battery weight provided by the manufacturer. If the battery is excessively heavy, the cells used are likely of questionable quality and are certainly not Grade A LiFePO4 Cells.

With the mass production of electric vehicles, many retired EV batteries are repurposed for energy storage. These cells have typically undergone thousands of charge cycles, significantly reducing the cycle life and state of health (SOH) of LiFePO4 cells, potentially leaving only 70% or less of their original capacity. If second-hand cells are used to manufacture home batteries, achieving the same 10kWh capacity would require more cells, resulting in a heavier battery.

By following these two steps, you’ll be able to become a professional battery expert that can confidently identify whether your battery is made with Grade A LiFePO4 Cells, making this method particularly useful for solar equipment distributors or mid-market customers.

Of course, if you are a professional in the renewable energy field with access to battery testing equipment, you can also evaluate other technical parameters such as capacity, internal resistance, self-discharge rate, and capacity recovery to more precisely determine the cell grade.

Final Tips

As the energy storage market continues to expand, more and more brands and manufacturers will emerge. When selecting a supplier, always be cautious of those offering suspiciously low prices or newly established companies, as they may pose a risk to your business. Some suppliers may even use Grade A LiFePO4 Cells to produce home batteries but exaggerate the actual capacity. For instance, a battery made with 3.2V 280Ah cells that forms a 51.2V 280Ah battery will have a capacity of 14.3kWh, but the supplier might advertise it as 15kWh because the capacities are close. This can mislead you into thinking you’re getting a 15kWh battery at a lower price, when in fact, it’s only 14.3kWh.

Choosing a reliable and professional home battery supplier is a challenging task. With so many options available, it’s easy to get overwhelmed. That’s why we recommend looking to BSLBATT, a manufacturer with over 20 years of experience in the battery industry. While our prices may not be the lowest, our product quality and service are guaranteed to leave a lasting impression. This is rooted in our brand vision: to provide the best lithium battery solutions, which is why we always insist on using Grade A LiFePO4 Cells.