China has published implementation requirements for the recommended national standard GB/T 46991.1-2025, which specifies accuracy and durability criteria for electric vehicle battery health display systems in light-duty passenger vehicles. Issued under the guidance of the Ministry of Industry and Information Technology and the Standardisation Administration of China, the standard was developed with technical input from a drafting group led by Yu Yang. Details were disclosed in a CCTV News report on August 2, 2026.
A primary focus of the standard is the accuracy of the State of Available Energy (SOCE) display. SOCE represents the ratio of a battery’s current available energy to its original factory-available energy, reflecting long-term capacity retention rather than real-time charge state. Under GB/T 46991.1-2025, the relative deviation between the SOCE value shown to drivers and the physically measured value must not exceed 5 percent. This requirement establishes a clear benchmark for comparing dashboard information with laboratory-measured battery capacity.
The standard also introduces a Virtual Mileage concept for non-driving discharge, converting energy consumed by vehicle systems and accessories while parked into an equivalent distance based on the vehicle’s standard energy consumption rate. Virtual Mileage displays must remain within a 3 percent deviation of measured results, although detailed testing conditions for specific accessory loads have not been publicly specified.
Durability benchmarks are defined by vehicle age and accumulated mileage. After 5 years and 100,000 km, batteries must retain at least 82 percent of their original available energy. After 8 years/160,000 km and 10 years/200,000 km, retention thresholds are set at 75 percent and 70 percent, respectively. These figures offer a uniform reference for long-term battery aging assessments.
As a recommended national standard, GB/T 46991.1-2025 focuses on evaluation and reporting requirements rather than mandatory enforcement or penalties. It complements mandatory safety regulations such as GB 38031-2025, which covers thermal runaway and other safety aspects. By harmonizing measurement methods for SOCE accuracy, Virtual Mileage calculation, and durability evaluation, the standard aims to enhance transparency in battery condition reporting and support more consistent practices in warranty discussions, used-vehicle valuations, and consumer decision-making.
Source: CarNewsChina
