CATL Chairman warned that shortened electric vehicle development progress would cause mass battery failures

The chairman of CATL warned that development progress would be shortened, causing many types of electric vehicle batteries to have mass failures.

Shortened development progress and the race to reduce prices are negatively affecting the quality of electric vehicle batteries in the Chinese market, according to a warning from CATL Chairman Robin Zeng in early September.

Speaking at the 2026 World Energy Battery Conference taking place in Yibin city, Sichuan province, Mr. Zeng said more than 600 new car models will be launched in China in 2026, equivalent to about three models per day. According to UDN, shortening the testing cycle to keep up with this speed is the reason why many battery lines have problems in batches. CATL leaders did not specifically name the vehicle manufacturers or battery suppliers involved.

The above warning was issued in the context that the Chinese electric vehicle market continues to be under strong pressure to reduce prices. Industry data records that the transaction prices of some popular electric vehicle models decreased significantly in the first half of 2026. Meanwhile, the price of LFP battery cells fell below 0.35 yuan/Wh (0.049 USD/Wh). This trend reflects the cost pressure on car manufacturers and suppliers, although there is not enough evidence to confirm that this is the direct cause of battery errors.

In fact, the Chinese market has recorded many battery quality disputes between car manufacturers and suppliers. In December 2025, Viridi E-Mobility Technology - a subsidiary of Geely - sued battery manufacturer Sunwoda for quality errors on battery cells supplied from June 2021 to December 2023, demanding compensation of 2.31 billion yuan (323 million USD). The case was later reconciled, Sunwoda agreed to pay 608 million yuan (89 million USD) after deducting previous payments.

Another case took place last July related to CALB's battery cells equipped on about 213,000 GAC Aion vehicles. Users constantly report battery swelling, loss of capacity and many other failures. This incident once caused a stir as the "banana battery" scandal because some battery cells were deformed and bent. After that, CALB had to announce the implementation of a series of measures to reform quality and tighten inspection.

The "wooden barrel" effect and error rate control threshold

CATL Chairman said that the traditional standard of controlling the defect rate in parts per million (PPM) is no longer suitable for the current large-scale production of electric vehicle batteries.

A battery pack consists of many battery cells connected in series and parallel. According to the "barrel effect", the operating range, charging capacity and thermal stability of the entire battery pack in series will be limited by the battery cell with the lowest capacity or highest impedance.

With a defect rate of 1 PPM, out of a billion battery cells produced, there will be up to 1,000 defective cells entering the assembly line. Therefore, a CATL representative shared that the company is applying an internal error control target of a maximum of 1 part per billion (1 PPB) for single battery cell production - which is 1,000 times stricter. This is an internal technical and production control index, not the actual failure rate on independently audited vehicles.

Technically, battery cell quality depends on controlling manufacturing variables to eliminate potential defects. CATL said it is using automated testing systems and strict process control to detect errors right in the production stage.

Previously, China's recommended standard GB/T 46991.1-2025 also specified the accuracy for State of Available Energy (SOAE), battery status indicators and expected range display (with errors not exceeding 5%).

The internal review group has the right to veto shipments

At the conference, Mr. Zeng also revealed about the Opposition Group (Duikangzu) - an internal criticism department maintained by CATL since its inception.

This team brings together experts from many fields such as electrochemistry, mechanics and artificial intelligence. The team's mission is to search for potential failure modes and test the battery system under the most extreme conditions.

Mr. Zeng affirmed that this group possesses unilateral veto power over project milestones and shipment decisions. However, CATL does not publicly disclose the organizational chart and direct management level of this department.

Challenges from record production scale

The warning from CATL leaders comes in the context that Chinese manufacturers account for more than 70% of installed energy battery production globally. According to data from SNE Research, the total installed battery capacity globally reached 608 GWh in the first half of 2026, with Chinese suppliers occupying 7 positions in the top 10.

At this huge production scale, even a very small error rate can lead to a large number of damaged battery cells entering the assembly process and appearing on vehicles in circulation. However, faulty battery cells on the production line do not necessarily lead to actual problems on the road, as additional testing, battery management systems and battery pack-level protection mechanisms can prevent or minimize the risk.

Besides, it is necessary to clearly distinguish between reliability at the battery cell level and safety at the whole vehicle level. Harsh single cell tests - such as penetration with a nail - are only intended to evaluate the ability to handle internal short circuits under laboratory conditions. These tests do not fully reflect the operating characteristics of the entire battery pack when subjected to actual impacts, which are accompanied by dynamic deformation, cracking of the protective cover or damage to the cooling system.

Previously, Chinese authorities' campaigns to suppress dirty information also targeted many social media accounts that posted non-standardized battery testing videos and made unverified statements that caused public confusion.

CATL Chairman's statements delve into a core technical and manufacturing question: whether the increasingly shortened vehicle development cycle still has enough time to detect battery defects before mass production. CATL's Target 1 PPB and counter-testing mechanism represent the quality control efforts that the company is committed to. Meanwhile, the legal and quality incidents that have occurred with Sunwoda or CALB are proof that the battery quality problem is still present in the Chinese electric vehicle market, although it cannot be confirmed that these incidents originate directly from the pressure to launch fast cars.