The head of CATL named the reasons for the decline in battery quality in China
Quick Look
- CATL chief Robin Zeng said accelerated development of electric vehicles and price competition in China are leading to lower battery quality due to shorter inspection cycles.
- He noted that more than 600 new EV models entered the market in the first half of 2026, and the company's internal benchmark is no more than one defect per billion cells, which is a thousand times stricter than the current standard of one defect per million.
AI-generated summary
Why It Matters
CATL is the world's largest battery manufacturer, and has previously faced controversies about battery quality, including Viridi E-Mobility's lawsuit against Sunwoda and problems with CALB batteries in GAC Aion cars.
The largest battery manufacturer named the main reasons for the decline in battery quality. CATL CEO Robin Zeng said China's accelerated development of electric vehicles and price competition are causing problems with battery quality in the domestic market, CarNewsChina writes.
He said that in the first half of 2026, more than 600 new models entered the local market. Reducing inspection cycles to achieve this pace led to failures in certain batches of traction batteries. He did not name the companies, brands and suppliers. By the way, Chinese manufacturers account for more than 70 percent of the global volume of installed batteries.
This is not the first time the topic of battery quality has arisen. In December 2025, Geely subsidiary Viridi E-Mobility Technology filed a lawsuit against battery manufacturer Sunwoda. She claimed to have discovered cell defects from June 2021 to December 2023 and demanded 2.31 billion yuan. The dispute was settled: Sunwoda agreed to pay 608 million yuan, taking into account losses already incurred.
In July of this year, it was reported that problems with CALB batteries affected about 213 thousand GAC Aion vehicles. Owners complained of bloating, loss of power and other malfunctions. Due to the curved shape of the cells, the name “banana battery” appeared. Over time, CALB announced changes to quality requirements and increased control.
Zeng said that the traditional parts per million defect tolerance is not enough for mass production of traction batteries. A battery is made up of cells connected in series and parallel, and due to the barrel effect, the performance of the unit is limited by the weakest cell with the smallest capacity or highest resistance.
At a rate of one defect per million, in a stream of a billion cells there may be up to one thousand defective. CATL, he says, has an internal target of no more than one defect per billion cells—exactly one thousand times lower. This is the internal reference point for engineers and production control.
What to Watch
AI outlook — possibilities, not facts
CATL will strengthen internal quality control and bring the defect rate to one per billion cells.
Likely · Within months
Open Questions
- What specific brands and suppliers have been affected by the decline in battery quality?
- What reputational damage has the company suffered from faulty batteries?
- When does CATL plan to reach its internal target of one defect per billion cells?
