China has officially released new technical guidelines regulating the accuracy of battery health indicator systems in light passenger electric vehicles. Through the recommended national standard coded GB/T 46991.1-2025, the local government aims to standardize the measurement method of remaining battery capacity so that the data displayed on the instrument panel aligns with actual conditions in the field.
This standardization was initiated by the Ministry of Industry and Information Technology of China (MIIT) together with the Standardization Administration of China (SAC). One of its main focuses is the regulation of the State of Available Energy (SOCE), which is the ratio of the battery's current energy capacity to its capacity when it was new. This regulation stipulates that the difference between the SOCE value displayed on the vehicle's screen and the physical test results must not exceed a five percent limit.
In addition to measuring long-term remaining power, the standard also formulates the concept of 'Virtual Mileage'. This formula functions to convert non-driving energy consumption—such as the use of air conditioning or electrical systems while the car is parked—into an equivalent mileage. For this indicator, the tolerance level for information deviation is set much tighter, at a maximum of three percent compared to actual measurements.
The document also formulates a reference for reasonable battery performance degradation based on vehicle age and mileage. As an illustration, a battery with an initial capacity of 100 kWh is targeted to retain at least 82 percent capacity (82 kWh) after five years of use or after reaching an accumulated distance of up to 100,000 kilometers.
Although it is a recommendation and does not carry legal sanctions or recall orders, the presence of the GB/T 46991.1-2025 standard is considered crucial for the automotive ecosystem. This regulation is expected to become an objective reference for warranty claims, long-term ownership feasibility assessments, and determining fair resale prices in the used electric car market.
