China Implements National Standard for Electric Vehicle Power Battery Durability

The national standard for durability of electric vehicle power batteries has been implemented. The standard defines the battery available energy state as the ratio of the battery's current actual usable energy to its usable energy when new; a higher value indicates greater available battery energy. The standard requires the battery available energy state to be displayed on-board and imposes a strict accuracy requirement: the displayed reading must not deviate from the vehicle's actual measured available energy state by more than 5%. In the verification process, the energy that the battery can discharge at the current stage is measured by running standard test cycles on a laboratory chassis dynamometer. Unlike battery cycle count, battery available energy state comprehensively reflects the real extent of battery degradation and is more closely aligned with users' perception of range decline.

The standard also introduces the concept of "virtual mileage." It measures battery discharge under non-driving conditions and, based on vehicle energy consumption, converts this discharged energy into an equivalent distance. The relative deviation between the virtual mileage converted value displayed by the vehicle and the measured value must not exceed 3%. For light-duty passenger vehicles, the standard sets the minimum durability performance requirements: after 5 years or 100,000 km of use, the battery available energy state should remain at least 82%; after 8 years or 160,000 km, at least 75%; and after 10 years or 200,000 km, at least 70%.