Summary of Key Issues
A total of 210,000 vehicles manufactured by GAC Aion, equipped with 177Ah lithium iron phosphate batteries produced by Zhongxin Innovation Aviation (mainly used for ride-hailing services), have experienced issues such as battery swelling, liquid leakage, and a significant drop in range. These problems have led to the batteries being nicknamed "banana batteries" within the repair community. The issues predominantly occurred after the vehicles had traveled 150,000 to 300,000 kilometers (just beyond the original warranty period), and third-party tests indicated manufacturing defects, including uneven coating of the battery electrodes and inadequate control of electrolyte moisture levels. Initially, the company refused to provide repairs on the grounds that the issues were outside the warranty period. However, after media exposure, GAC Aion extended the warranty to 8 years and 300,000 kilometers but did not initiate a recall. This incident highlights Zhongxin Innovation Aviation's focus on reducing costs and securing orders at the expense of quality control, as well as the industry's lack of specialized testing for batteries used in commercial vehicles.
Detailed Analysis
Why Do "Banana Batteries" Swell?
The swelling of batteries is similar to that of a banana, caused by internal gas generation that expands the battery cells. Lithium-ion batteries contain a substance called VC (Vulcanizing Carbon), which forms a protective layer (SEI film) on the negative electrode to prevent the solvent from damaging the electrodes. If VC is depleted prematurely, the negative electrode begins to decompose the solvent, producing gas and causing the battery cell to expand.
There are two possible reasons for the premature depletion of VC: first, the use of cheaper graphite materials in the negative electrode, which accelerates VC consumption; second, poor control of electrolyte moisture during manufacturing, which undermines the protective effect of VC. These batteries were produced in 2021, and at that time, the industry had not specifically designed them for the high-frequency charging and heavy-duty conditions associated with ride-hailing services, leading to the issues emerging several years later.
Why Did the Problem Only Become Public Now?
The difference in warranty periods between consumer vehicles and commercial vehicles (such as those used for ride-hailing) is a critical factor. Commercial vehicles often travel hundreds of kilometers daily, reaching 150,000 kilometers within 1 to 2 years, which coincides with the time when these batteries started to fail. Initially, companies refused repairs on the grounds that the issues were beyond the warranty period, and owners had to pay thousands of yuan to replace the batteries out of their own pockets. It was only after Xinhua News Agency reported the issue that GAC Aion extended the warranty within four days.
The key contradiction here is that the usage patterns of consumer and commercial vehicles are vastly different, but the battery design and testing did not account for these differences. For example, while a consumer vehicle may travel 50 kilometers a day, a ride-hailing vehicle might travel 500 kilometers daily and frequently use fast charging, resulting in much faster battery degradation. However, there were no regulatory requirements or industry standards to address this disparity, leading to the problems surfacing at the end of the warranty period.
Why Was There No Recall?
A recall is a legal requirement that involves formal notification to regulatory authorities and follows strict procedures. Companies chose to extend the warranty and provide free repairs instead of recalling the batteries for two main reasons:
- They considered these issues to be related to specific usage conditions rather than safety defects (such as fires or explosions).
- The new national standards were not implemented until July 2026, so the vehicles from 2021 to 2023 were not subject to the newer requirements.
In essence, extending the warranty was a more flexible and less costly alternative to a recall, which also avoided potential negative brand impacts.
Zhongxin Innovation Aviation's Growth Challenges
Zhongxin Innovation Aviation has become the third-largest battery manufacturer in China, largely due to GAC Aion's support (as a competing supplier to CATL) and its ability to secure orders at lower prices. However, rapid expansion has created several challenges:
- High dependence on a single customer: GAC Aion once accounted for more than 50% of Zhongxin Innovation Aviation's revenue, leading to price cuts and cost-cutting measures, such as using cheaper negative electrode materials.
- Rapid capacity expansion: The company built factories in multiple locations after going public in 2022, and the 177Ah batteries were launched amidst a busy period of financing, IPOs, and capacity expansions. As a result, testing may not have been comprehensive enough.
- Insufficient R&D investment: In 2025, Zhongxin Innovation Aviation's R&D expenditure was only 4.83%, compared to CATL's 5.23% and Guoxuan High-Tech's 7.47%. This lack of investment in research and development has hindered its ability to maintain quality as it expanded.
This incident tests Zhongxin Innovation Aviation's commitment to quality; with its growth, can it maintain the same standards?
Industry Insights
The "banana battery" issue highlights a gap in industry standards: current battery regulations do not differentiate between consumer and commercial usage scenarios. The high usage intensity of ride-hailing vehicles far exceeds that of regular cars, but battery manufacturers typically only conduct tests when prompted by automakers. It was not until 2023 that BYD began developing batteries specifically for ride-hailing applications. Zhongxin Innovation Aviation's batteries from 2021 did not meet these new standards. Although the new national standards have improved safety requirements, they are not retroactive and do not apply to existing vehicles. In the future, the industry may need to establish separate testing standards for commercial vehicle batteries, and automakers should actively require suppliers to conduct scenario-specific tests to prevent similar issues from occurring.
Conclusion
The "banana battery" incident is not a isolated quality issue but reflects broader challenges in the new energy vehicle sector: companies often sacrifice quality control to gain market share and reduce costs, and industry standards lag behind real-world usage patterns. Consumers need clearer protections for their rights as owners of commercial vehicles. Companies must not compromise on quality during expansion, and the industry must develop more tailored standards for different usage scenarios.