We finally have the latest updates on our 4-month long-term cycle test of three batteries! Today, I'm going to break down the actual test data of the EVE 628AH 3.2V lithium battery, CATL 530AH 3.2V lithium battery, and 200AH 3V sodium-ion battery in detail. We'll focus on calculating the capacity attenuation rate of each battery to see which one performs the best!
First, a quick reminder: the initial test conditions for the three batteries (except for the voltage range) are consistent—all using 30A discharge. I shared the initial test data with you in previous videos. Today, we'll focus on the core results of the subsequent cycle tests. At the same time, we'll exclude abnormal data caused by equipment failures to ensure the accuracy of the conclusions.
1. EVE 628AH 3.2V Lithium Battery: 22 Cycles, Attenuation Rate 2.21%The initial capacity test of this battery (voltage range 2.5-3.65V) reached 680AH, with 30A discharge lasting a full 40 hours, showing a very impressive initial performance. Subsequently, we conducted 22 capacity cycle tests, and the actual measured data are as follows: 671, 675, 674, 670, 670, 464, 667, 670, 670, 669, 669, 668, 667, 668, 668, 668, 669, 666, 669, 596, 668, 665.
Initial：
Post-Cycle：
It must be noted here: the 464AH and 596AH in the data were caused by malfunctions of the capacity grading equipment during the test, which are invalid data and will be directly excluded. After exclusion, it can be seen that the maximum capacity of the battery was the initial 680AH. After 22 cycles, the current stable capacity is 665AH, with a cumulative attenuation of 15AH.
「Attenuation Rate Calculation」: (Initial Maximum Capacity - Current Stable Capacity) ÷ Initial Maximum Capacity × 100% = (680 - 665) ÷ 680 × 100% ≈ 2.21%. Let's combine this with industry standards. The industry generally requires the 100-cycle attenuation rate to be ≤ 2%, which translates to an allowable attenuation rate of about 0.02% per cycle. However, the total attenuation rate of this EVE battery after 22 cycles is only 2.21%, which translates to an approximate 10.05% attenuation rate for 100 cycles? No, a more intuitive way is: reaching 2.21% attenuation after 22 cycles may seem not low, but it should be noted that most batteries only approach the 2% attenuation threshold after 100 cycles. Even after 22 cycles, EVE can maintain this level, so its actual attenuation performance is far better than the industry standard of ≤ 2% for 100-cycle attenuation rate, and the overall performance is quite excellent.
A quick supplement: this EVE 628AH comes with a real QR code. We purchased it through market channels, and the supplier claims it is a laboratory test-grade premium A product, but everyone can judge the specific source by themselves—I only present the test data objectively.
2. CATL 530AH 3.2V Lithium Battery (Grade B): 27 Cycles, Attenuation Rate 1.30%, Performance Is Super Amazing!As the only Grade B battery among the three (re-coded by the supplier, which I detailed in previous videos), the performance of the CATL 530AH has definitely exceeded expectations! The initial capacity grading test (voltage range 2.5-3.65V) showed a capacity of 537AH, with 30A discharge lasting more than 30 hours. A total of 27 capacity cycle tests were completed subsequently, and the data are as follows: 540, 539, 539, 539, 538, 537, 333, 539, 537, 536, 536, 536, 535, 534, 534, 534, 534, 536, 535, 533, 533, 533, 459, 533, 533, 533.
Initial：
Post-Cycle：
Similarly, excluding abnormal data caused by equipment failures (333AH, 459AH), we can see that the maximum capacity of this battery reached 540AH. After 27 cycles, the current stable capacity is 533AH, with a cumulative attenuation of only 7AH.
「Attenuation Rate Calculation」: (Maximum Capacity - Current Stable Capacity) ÷ Maximum Capacity × 100% = (540 - 533) ÷ 540 × 100% ≈ 1.30%. How amazing is this data? Let's first compare it with the EVE 628AH tested in the same batch, which had an attenuation rate of 2.21% after 22 cycles. The CATL 530AH not only has 5 more cycles (27 vs 22) but also has an attenuation rate nearly 1 percentage point lower. Just looking at the competition between lithium iron phosphate batteries, CATL's attenuation control ability is directly one level ahead. More importantly, this CATL 530AH is not a brand-new Grade A product, but a re-coded Grade B battery by the supplier—friends familiar with the battery industry know that Grade B batteries are usually screened out due to minor appearance defects or slight parameter deviations. Many people in the market worry about their stability and attenuation performance, but our actual test data have completely dispelled this concern. After 27 cycles, it only attenuates by 7AH, and the capacity is stable at 533AH, which is even higher than its initial nominal 530AH, completely not affecting the actual use experience. Combined with the industry's general standard of ≤ 2% for 100-cycle attenuation rate, the attenuation rate of this CATL Grade B battery is only 1.30% after 27 cycles, which translates to an approximate 4.81% attenuation rate for 100 cycles. It is not only far lower than the industry threshold but also performs better than many brand-new Grade A batteries on the market. This "dimension-reducing strike" level of stability can really be described as "maxed out"!
3. Sodium-Ion Battery 200AH 3V: 66 Cycles, Attenuation Rate 2.43%, Stability Is Called the "King of Rollers"!Finally, let's look at the sodium-ion battery. The initial capacity grading data is 206AH, with a test voltage range of 2-3.8V and 30A discharge. The subsequent cycle test data is overall very stable: 206, 206, 206, 206, 206, 206, 205, 206, 206, 207, 208, 208, 207, 207, 207, 208, 206……206, 206, 204, 204, 205, 205, 204, 204, 205, 205, 205, 204, 204, 204, 203, 204, 205, 203, 204, 203.
Initial：
Post-Cycle：
The number of cycles of this battery is the highest among the three, completing a full 66 cycles! Among them, the maximum capacity reached 208AH, the minimum capacity was 203AH, and the cumulative attenuation was 5AH.
「Attenuation Rate Calculation」: (Maximum Capacity - Minimum Capacity) ÷ Maximum Capacity × 100% = (208 - 203) ÷ 208 × 100% ≈ 2.43%. It should be noted here that the capacity fluctuation of the sodium-ion battery is extremely small throughout the process, and the attenuation curve is almost flat. A 2.43% attenuation rate is an excellent level in long-cycle tests, fully reflecting the unique advantage of sodium-ion batteries in stability.
4. Summary of Core Data & Conclusions of the Three BatteriesFirst, let's summarize the core data for everyone, which is clear at a glance:
The conclusion is clear: after long-term cycle tests, the attenuation rates of the three batteries are all within a reasonable range, with no abnormal attenuation. Their quality can stand the test! However, when compared horizontally, the gap is very obvious:
Finally, a reminder: our test is still ongoing. We will continue to track the long-term attenuation of these three batteries and their performance in different environments. If you want to know the most real battery test data and pit avoidance guides, remember to like + follow, and we'll see you in the next video!
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