Research on Rapid Cycle Test Method in Low-Temperature of Electric Vehicle Driving Range Based on China Light-Duty Vehicle Test Cycle

The increase in battery storage capacity of electric vehicles has led to longer electric vehicle range testing duration at low temperatures. To shorten testing duration and lower costs, a rapid and accurate method for electric vehicle range testing at low temperature was developed. First, electric range testing on 15 vehicles were conducted at −7 ℃ according to consecutive cycle test method in GB/T 18386.1-2021, the test cycle is China light-duty vehicle test cycle. The results showed different discharge characteristics at −7 ℃ compared to at 23 ℃. Differences are summarized as: more cycles needed for achieving thermal equilibrium and battery pack heating in the last discharge stage. To address the former difference, by setting various representative cycle numbers and weighting coefficients, it determined a rapid cycle test method that includes a dynamic segment and a constant speed segment. To address the latter difference, it developed the abnormal energy correction method. Practical experiments have validated that the new method ensured a range test deviation within 3%. It effectively reduced the test duration by over 50%. In conclusion, the rapid cycle test provides an efficient and accurate method for electric vehicle range testing in low-temperature, significantly reducing test duration and suitable for all vehicles.