The penalty in energy consumption of battery electric vehicles operating at subzero temperatures

Abstract

AbstractChassis dynamometer test results of a plug‐in battery‐electric vehicle are coupled to a Newton equation analysis. Propulsive and braking mechanical powers are computed and compared to the electric power in and out of the battery. We consider a 53.4 km reference driving cycle, comprising UDDS, Hwy, UDDS, and US06 cycles completed in sequence with different ambient temperatures, −6°C, 23°C, and 35°C. At −6°C, the battery energy used is ΔEe = 40.41 MJ, the propulsive efficiency is ηp = 0.62, and the regenerative braking efficiency is ηrb = 0.51. At 23°C, ΔEe = 22.78 MJ, ηp = 0.94, and ηrb = 0.84. Finally, at 35°C, ΔEe = 25.47 MJ, ηp = 0.88, and ηrb = 0.77. These results show as the temperature has a major influence on the energy efficiency of a BEV, with colder conditions translating in dramatically higher energy consumption, and warmer conditions also producing an increment in energy consumption. This is the result of the temperature‐dependent battery performance and cabin cooling or heating. Once the total energy consumption penalty is depurated of the energy needed to run the auxiliaries, primarily cabin cooling, and heating, there is a large effect of very cold temperature that calls for better heating strategies for BEV sold in cold‐weather markets.