Characterizing BEV energy flow in extreme climates: An experimental comparison of heat pump, PTC, and hybrid thermal management architectures

The energy efficiency of Battery Electric Vehicles (BEVs) is highly sensitive to ambient temperature, yet publicly available systematic experimental data on BEV energy flow across wide ambient temperature ranges, particularly below −20 ∘C, remain scarce. This study conducts chassis-dynamometer experiments on three production BEVs employing Heat Pump (HP) only, Positive Temperature Coefficient (PTC) heater dominated, and hybrid HP+PTC thermal management architectures, respectively. Tests are performed under the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) at four ambient temperatures: −25 ∘C, −7 ∘C, 23 ∘C, and 35 ∘C. The principal findings are as follows. (1) Across the four tested setpoints, energy consumption per 100 km increases on both sides of the 23 ∘C baseline, with a markedly steeper gradient on the cold side: at −25 ∘C, consumption rises by 88.65%–143.45% relative to the 23 ∘C baseline. (2) Energy flow analysis reveals that the thermal management share surges from near zero at 23 ∘C to 40.09% at −25 ∘C, triggering a structural shift from a traction-dominated to a drive-plus-heating dual-load regime. (3) Among the three tested vehicles, the one equipped with the hybrid HP+PTC architecture exhibits 61.99% lower thermal management consumption than the PTC-dominated vehicle; however, this outcome is simultaneously influenced by differences in battery chemistry, vehicle type, and control strategy. (4) Regenerative braking recovery rates and fast-charging power decline markedly at −25 ∘C. Under the tested vehicles’ default production control logic, the concurrent “heat-while-charge” preheating strategy is associated with up to 66.16% shorter total charging time compared with the sequential “preheat-then-charge” approach.