A study by Austria-based Aviloo showed that electric vehicle (EV) batteries may last longer than drivers expect. Across 20 popular models, the median usable capacity remained between 87-94% after 150,000 km, 91-97% after 50,000 km, and 88-95% after 100,000 km. The result indicated that the vehicles could retain approximately 90% capacity.
The study is based on more than 500,000 tests conducted worldwide between 2022 and 2026 on 20 models, including the Tesla Model Y and Volkswagen ID.4; Chinese models were excluded due to insufficient data. Battery warranties generally cover eight years or 100,000 miles (160,000 km) and require the manufacturer to replace the battery if capacity falls below 70%.
Battery degradation was found to vary even within the same model depending on factors such as climate, battery size, and usage habits, including parking. In the Nissan Leaf ZE1, the difference after 150,000 km reached 13.5 percentage points, equivalent to a range difference of approximately 29 km per charge. The difference was measured at 11 percentage points in the Tesla Model Y, 11-12 in the Volkswagen ID.4, and more than 12 in the Hyundai Ioniq 5.
Aviloo reported that hot climates and parking vehicles at high charge levels accelerate degradation, and that the ideal level is 30-70%. Three major EV organizations in the United Kingdom also called for mandatory battery health certificates.
Why it matters
These findings show that battery health cannot be assessed solely by mileage for electric vehicle owners; operating conditions can also create significant differences before the warranty threshold is approached. Linking warranty coverage to capacity falling below 70% makes it necessary for measurement methods and vehicle history to become more transparent to drivers. The call from organizations in the United Kingdom for health certificates shows that the issue is not merely a matter of user preference, but also one of documenting and monitoring battery condition. However, the results are limited to 20 models and do not include Chinese models; therefore, it is not possible to generalize them to the entire market. The open question is how different climates and usage patterns will be standardized in warranty assessments and whether health certificates will become mandatory.