"Deadly" battery cells: The tricks behind the collective failure of non-3C power banks
Overnight, all power banks without the 3C logo on their casings can no longer be taken on airplanes. These perfectly good power banks have suddenly become useless "bricks."
On June 26th, the Civil Aviation Administration of China issued a notice stating that starting from June 28th, passengers are prohibited from carrying power banks without a 3C logo, with unclear 3C logos, or those of recalled models or batches on domestic flights.
"This recall is very rare. In the domestic mobile power bank industry, there is no mandatory regulation requiring the recall of products with problems. If a product is unqualified, the administrative department for industry and commerce can impose penalties and suspend the 3C certificate, but there is no regulation mandating a recall." Li Jingfeng (a pseudonym), a senior expert in the power bank industry, told Zhiwei.
Starting from a power bank self - ignition incident on an airplane in March, it triggered a thorough investigation that affected the entire industry. Subsequently, the 3C certificates of many upstream and downstream brand products were suspended, the production qualifications of raw material suppliers were revoked, and even the certification - issuing qualifications of several testing institutions were cancelled. Romoss and Anker Innovations successively chose to recall their relevant products.
How exactly did this earthquake that affected the entire industry occur? Why do safety issues with power banks occur repeatedly? Regarding these questions, Zhiwei contacted multiple people related to the power bank supply chain and brands, attempting to explore the answers behind them.
"Surprise Inspections" Sweep through the Power Bank Supply Chain
"It all started because on March 20th, on a flight from Hangzhou to Hong Kong, a passenger's power bank caught fire, and this power bank was exactly a Romoss product." Li Jingfeng revealed.
At the beginning of June, 21 universities in Beijing issued a notice banning the use of Romoss 20000mAh power banks, stating that multiple self - ignition cases had caused property losses.
Multiple industry insiders confirmed to Zhiwei that around May, the State Administration for Market Regulation began to commission relevant departments and testing institutions to conduct at least two surprise inspections on power bank cell factories and finished product factories, randomly sampling and sealing on - site products.
That is to say, the inspections are not announced in advance.
During this two - month surprise inspection process, Anpuleisi, the largest domestic supplier of soft - pack batteries for power banks, was found to have a discrepancy between the procurement list of a certain Jiangxi factory it cooperated with and the raw material list provided during the inspection.
Generally, there is a CDF list (Critical Component List) during power bank certification, and these critical components should not be replaced during production and assembly.
Among them, the battery cell is one of the most important parts of a power bank. According to supply chain insiders, generally, the cost of the battery cell accounts for at least one - third of the total cost of the power bank.
Affected by this, more than 70 3C certification certificates for batteries and cells under Anpuleisi were successively marked as suspended or revoked. The 3C certifications of mobile power banks of multiple leading brands such as Romoss, Anker Innovations, Xiaomi, Ugreen, and Baseus were also suspended or revoked.
Zhiwei found that most of the 3C certifications were suspended in June. The reasons for the suspension of certification shown by the certification - issuing institutions were mainly: "The factory supervision inspection failed, there were serious non - conformities in the factory inspection (such as problems with product consistency) or the non - conformity report of the factory inspection did not take corrective measures within the specified time limit and report to the inspection team for verification and effectiveness."
Li Jingfeng said, "As far as we know, the two specifications of cells with problems are 126280 and 676076. There is no feedback yet indicating a risk of combustion or fire for other specifications."
Another leading power bank brand told Zhiwei that the only cell specification with risks in its brand was 126280.
"Deadly" Battery Cells
The so - called 126280 is a soft - pack lithium - polymer battery cell, named after its physical dimensions, that is, thickness 12mm × width 62mm × length 80mm. Generally, the higher the energy density, the stronger the activity, and the corresponding increase in danger. The parameters such as the size, capacity, and energy density of this specification of cell have been specially optimized and are suitable for products that pursue thinness, portability, and undiminished capacity.
The rated capacity of a single cell of this type is 10000 mAh. Many power banks on the market also achieve a capacity of 20000 mAh through technical superposition.
Anpuleisi (Wuxi) Co., Ltd., the cell enterprise with problems this time, is located in Wuxi, Jiangsu. It was jointly funded and established in 2014 by a wholly - owned subsidiary of Amprius in the United States and Wuxi Industrial Development Group Co., Ltd. It has a unique leading position in the lithium - ion battery industry and is the largest domestic supplier of soft - pack batteries in the power bank field.
According to Li Jingfeng's knowledge, Anpuleisi has cumulatively shipped over 100 million pieces of the two cell models mentioned above.
Another person related to a power bank manufacturer told Zhiwei that the estimated shipment volume of the risky batches was around 20 - 30 million pieces.
Yang Yan (a pseudonym), an employee of a cell supplier, told Zhiwei that this incident was mainly due to the factory replacing the raw materials of the separator between the cathode and anode of the battery, resulting in a risk of failure of the battery's positive - negative separator.
"You can understand the cell as a 12 - millimeter - thick cloth. One side is coated with positive electrode material, and the other side is coated with negative electrode material. The insulation between the positive and negative electrode materials depends on a separator. You can simply understand this separator as a very thin plastic film. Then, when it is wound, it becomes insulated."
There are reports that the contract manufacturer may have replaced the ceramic - coated PP/PE separator with a common PP/PE separator, but it is temporarily impossible to obtain an exact response and confirmation from the relevant parties. Zhiwei found that in May 2022, Anpuleisi applied for a patent for "a composite film and a lithium - ion battery containing the film."
"After the material is replaced, since this material has not been verified, the reaction between the positive and negative electrodes is different from before. The most common situation is that the 'needles' (lithium dendrites) generated can easily pierce the separator, causing the cell to short - circuit." Yang Yan explained. This makes the power bank more prone to overheating, bulging, catching fire, and self - igniting. If the flame - retardancy of the power bank casing also fails to meet the standard, the harm is likely to expand.
Generally, these "needles" (lithium dendrites) cannot be completely eliminated. They are generated during the normal use of the power bank. However, if the power bank is produced according to mature processes, in a strict environment, and with specified materials, it can meet the national standard requirements and be safe enough during use.
Yang Yan guessed that in addition to the replacement of the separator material, the contract manufacturer may also have replaced the high - nickel ternary cathode material with other materials. Anpuleisi's cells generally use high - nickel ternary materials plus silicon - carbon anodes, which can have a very high energy density. The silicon anode is Anpuleisi's patent barrier, and replacement would lead to a sharp decline in performance, so the possibility of replacement is extremely low.
High - nickel materials have very strict environmental requirements during the production process. For example, a slightly higher humidity can cause them to clump together, leading to a short - circuit.
"Many factories have a very high defective rate because they cannot control the humidity during the production process well." Yang Yan said.
As for whether Anpuleisi and power bank brands will test the power banks produced from the cell batches of the contract manufacturer, Yang Yan believes that testing will definitely be carried out, but it may not be easy to detect problems.
"There will be inspections, but this kind of cell accident is delayed. It is impossible to detect problems immediately after getting the cell. It takes time to use the power bank for the problems to emerge. If the material is only replaced by 1/3 or even slightly adjusted, it is difficult to detect."
In fact, according to the normal contract process, if the contract manufacturer wants to replace materials, it needs to report to the original factory first. Then, the original factory will conduct tests to see if it can pass. Only after that can the new material be used. And according to the regulations of the 3C certification, the replacement of the raw material list also needs to be reported.
According to insiders, around May this year, Anker Innovations found that there were risks in certain batches of power banks based on user feedback. After an internal inspection, it was found that there were problems with some batches of cells from Anpuleisi. After reporting to the relevant departments, it recalled the products immediately.
Zhiwei learned that the high - risk batches of cells have a pattern when leaving the factory. In the early stage after the contract is signed, the quality of the cells is normal, and the probability of high - risk batches of cells increases significantly in the later stage of the contract. Overall, the problems with Anpuleisi's 126280 - specification cells have been particularly serious in the past year. If we trace back based on the time of leaving the factory and consumer use, the production time of high - risk cells may be between 2023 and 2024.
After the incident, the contract manufacturer's production qualification was immediately revoked. Currently, external information cannot confirm whether Anpuleisi was aware of the problem of the contract manufacturer replacing materials in the cells.
Since the 126280 cells are widely used in basic - model power banks on the market and have a large production volume, industry insiders said that at least forty or fifty brands use these cells, not including other white - label manufacturers.
As of June 26th, in addition to Romoss, which is at the center of the storm, announcing the recall of 490,000 power banks with safety hazards, only Anker Innovations has actively issued a recall notice, with a quantity of 713,000 units.
The dozens of other affected brands, many of which are well - known to the public, have not issued a public statement to consumers for the time being.
According to insiders, relevant departments have held meetings to interview relevant brands for follow - up cooperation and investigations.
Whose Fault Is It?
Yang Yan said that currently, the outsourcing of power bank cell production is very common in the industry. The consumer electronics industry is developing very rapidly. Batteries are one of the most important components of all electronic products. However, building a production line is not a quick process. It requires large investments and a long cycle.
Taking Anpuleisi's lithium - ion and sodium - ion battery technology transformation project as an example, from planning to the approval of the environmental impact assessment, with a total investment of 1.05 billion yuan, the project started on August 28, 2023, and the environmental impact assessment was approved on August 22, 2024, taking about one year.
A supplier of Anpuleisi revealed that Anpuleisi's in - house cell production capacity is 600,000 per week, about 2.4 million per month. The market demand far exceeds this. This requires contract manufacturers to undertake the overflowing production capacity.
"Power bank manufacturers also know that cell factories have many contract manufacturers." Yang Yan said.
However, the problem is that from production to market launch, the only national - level test a power bank truly undergoes is the 3C certification, which has been mandatory since August 1st last year.
This means that as long as a power bank obtains the 3C certification before market launch, in fact, the entire process from production to market launch is basically the responsibility of the manufacturer and the brand itself.
After obtaining the 3C certification, it is easy for the cell to be replaced during sales, while the label still shows the model submitted for inspection.
In the testing standards, the lack of mandatory and scientific testing for some key components has created loopholes for actions such as material replacement. Currently, the 3C safety certification for mobile power banks is mainly based on GB 31241—2022 and GB 4943.1—2022.
"It's very similar to some drug tests. Replacing materials may only meet the standards in some framework indicators, but the real situation is not so." Li Jingfeng said.
"Because brands only need to face the annual random inspections by the relevant departments. Even if they fail the random inspection, they are only fined a few thousand yuan. However, for a popular power bank, it can sell hundreds of thousands of units per month. Assuming that replacing a cell can save 5 yuan, it can save more than one million yuan per month."
"In addition, the competition among 3C certification institutions is also very fierce, and the cost has dropped to between 6,000 and 18,000 yuan."
At this point, you will understand why the power banks without 3C certification in your hands are more dangerous. Before the mandatory implementation of the 3C certification, they even wanted to save this small amount of certification fees, and it is highly likely that they saved on materials as much as possible.
There is even a possibility that the quality of these products simply cannot pass the 3C certification.
Multiple industry insiders told Zhiwei that the increasingly fierce industry involution has made manufacturers somewhat neglect the importance of product safety testing, especially when facing a manufacturer like Anpuleisi with high - barrier technological advantages.
To stay in the game, manufacturers need to compress costs, produce faster - charging products with lower prices and higher power. Only with large sales volumes can they consider profits.
"For comparison, the cells used in mobile phones are generally much better than those in power banks, but the usage environment of power banks is much harsher than that of mobile phones. The output power of a mobile phone is at most 10 watts, while the output power of a power bank can easily reach 20 - 30 watts, but the price of its cells is even cheaper than that of mobile phone cells." Li Jingfeng believes that this is the impossible triangle of volume, power, and price.
"Currently, the cost of a 5000 - mAh cell for a power bank is about a dozen yuan, and the cell cost accounts for 30% - 50% of the total cost of the power bank. However, the industry has become so competitive that a 20,000 - mAh, 33 - watt power bank is sold for only 100 yuan." Li Jingfeng believes that in this environment of involution and lax supervision, accidents are almost predictable.
To ensure safety as much as possible while meeting the increasing user requirements, only better cells can be used. "For example, using ATL or Guangyu cells, but obviously, the cost will increase." Li Jingfeng said.
Currently, both enterprises and policy - makers have made obvious attempts at full - link regulatory coordination and issued relevant rules.
In June, when the recall was announced, Anker Innovations signed a strategic cooperation agreement with ATL, designating ATL as the core power bank cell supplier. The first - batch procurement volume is 45 million pieces, with a procurement amount of over 100 million US dollars.
On June 18th, the website of the Ministry of Industry and Information Technology publicly solicited opinions on 17 mandatory national standards for mobile power banks for formulation and revision.
The proposed standard aims to improve the safety of mobile power banks from five aspects: testing, materials, processes, lithium dendrite monitoring, and safety information monitoring functions such as voltage and temperature. It also adds or tightens the test requirements for over - charging, needle - piercing, extrusion, and thermal abuse of power banks.
After this new round of industry reshuffle through survival of the fittest, this June may be the darkest moment for the industry.
Of course, the large - scale demand for users to update their power banks is also the rebirth day of the industry.