Recently, the power bank industry has experienced an unprecedented safety crisis. In June 2025, several brands announced the recall of power bank products with safety hazards, with a total of more than 1.2 million units recalled, setting a record in the industry. This incident has aroused great concern in the whole society about the safety of power banks. Many airlines have urgently issued new regulations to prohibit power banks without 3C certification or recalled batches from boarding.
The reasons for the recall point to two core issues: defects in raw materials for the battery cells and failure of the circuit protection system . An announcement pointed out that "due to the source of raw materials for some battery cells, a very small number of products may overheat during use, which may cause combustion risks in extreme scenarios." Another brand disclosed that "some batches of industry-standard batteries from a certain supplier had unapproved raw material changes," resulting in "diaphragm insulation failure after long-term cyclic use." Behind these problems, a key but often overlooked factor is the use of inferior MOS tubes.
1. Defects in battery cell raw materials
According to multiple sources, the main problem of this recall is the battery cell. As the core component of the power bank, the battery cell occupies more than 90% of the space inside the product, and its quality directly affects the safety of the entire product.
2. Circuit protection system failure
On the basis of the quality defects of the battery core, the inferior MOS tube becomes an amplifier of safety hazards. MOS tube plays multiple key roles in the power bank circuit: ===========
Charge and discharge control: managing the process of current flowing into and out of the battery cell
Temperature monitoring: prevent overcharging, overdischarging and overheating of batteries
Short circuit protection: quickly cut off the circuit in abnormal conditions
Poor-quality MOS tubes are prone to breakdown failure under high temperature and high voltage scenarios, causing a complete breakdown of the protection circuit. In the experiment, the temperature of a power bank using inferior MOS tubes soared to over 400°C in just 15 seconds under a short-circuit state, posing a risk of combustion. When the insulation performance of the battery cell diaphragm decreases due to raw material problems, the failed MOS tube cannot cut off the circuit in time, and the heat continues to accumulate, eventually leading to thermal runaway.
3. Quality compromise under cost pressure
Vicious price competition in the industry has caused some manufacturers to compromise on key components:
Experts from the China Battery Industry Association pointed out: "The cost of battery cells accounts for more than 60% of the total cost of mobile power supplies. In pursuit of higher profits, some manufacturers tend to choose low-priced battery cell suppliers." This phenomenon also applies to the purchase of MOS tubes.
Three fatal defects of inferior MOS tubes
Through the analysis of recalled products, inferior MOS tubes mainly have the following safety hazards:
1. Insufficient thermal stability
High-quality MOS tubes can work stably in a high-temperature environment of 85-125°C, while inferior products will experience performance degradation or even failure at 55-70°C. In the enclosed space inside the power bank, the ambient temperature can easily exceed the critical value.
2. Switch response delay
When an abnormality occurs in the circuit, high-quality MOS tubes can cut off the current in microseconds, while the response time of inferior products may be delayed by 10-100 times, and thermal runaway cannot be prevented in time.
3. Unstable internal resistance
The internal resistance of inferior MOS tubes increases sharply under high load, causing local overheating and then breakdown, forming a vicious cycle.
A typical power bank safety accident usually goes through the following stages:
Defects in battery cell materials lead to local heating
The temperature sensor detects an abnormality but the MOS tube responds with a delay
The increase in internal resistance of inferior MOS tubes exacerbates local high MOS tube breakdown causes complete failure of protection circuit
Thermal runaway causes combustion or explosion
According to the civil aviation accident investigation report, in the fire incident on a Hangzhou-Hong Kong flight in March 2025, it was the inferior MOS tube that failed to cut off the faulty circuit in time, causing the power bank to run away from heat.
Solution: Use high-quality MOS tubes to improve safety
VBsemi MOS tube professional technical advantages
In response to the safety requirements of power banks, VBsemi MOS tubes provide
Ultra-low on-resistance : only 2.8mΩ, reducing heat generation by 40%
High temperature stability: can work stably in the environment of -55℃ to 175℃
Nanosecond response: abnormal current cut-off speed is as fast as 20ns
Multiple protection mechanisms: integrated over-temperature, over-current, and short-circuit triple protection
Implementation recommendations
Power bank manufacturers should improve the quality of MOS tubes from three aspects:
Supply chain management: Establish a core component supplier certification system to avoid the use of uncertified substitute materials
Production process control: Add AOI inspection points in the SMT patch process to ensure the welding quality of MOS tubes
Aging test : 72-hour high temperature and high humidity cycle test to detect potential defects in advance
Regulatory upgrades
Starting from August 1, 2024, my country will officially implement mandatory CCC certification for power banks.
The new regulations require:
All power banks must pass CCC certification
Key components (including MOS tubes) need to establish a traceability system
Manufacturing companies need to have their own factories and complete quality control systems
The Civil Aviation Administration has simultaneously implemented new regulations, prohibiting power banks without 3C logos, unclear logos or recalled power banks from being taken on board.
To reduce safety risks, consumers should pay attention to:
Check whether the product has a clear CCC certification mark
Avoid buying abnormally cheap large-capacity power banks
Check the power bank regularly to see if it is swollen or overheated.
Avoid long-term charging (no more than 24 hours)
If you find a recalled product, stop using it immediately and contact the manufacturer
The recent large-scale recall of power banks has exposed the industry's serious defects in the quality control of core components. In addition to the problem of raw materials for battery cells, the failure of protection circuits caused by inferior MOS tubes is a key amplifier of safety hazards. Selecting high-quality MOS tube products, combined with strict supply chain management and production control, can significantly improve the safety of power banks.
As the People's Daily commented: "Recalling defective products is only the first step. Power banks should solve power anxiety rather than create safety anxiety." The industry must engrave "safety is the bottom line" into its DNA and establish core competitiveness through technological innovation rather than cost compression. Only through the concerted efforts of the entire industry chain can we rebuild consumer confidence and promote the healthy and sustainable development of the industry.
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