On the Thermal Behavior of Headlamps in Battery Electric Vehicles – An Experimental Study

<div class="section abstract"><div class="htmlview paragraph">Automotive headlamps in Battery Electric Vehicles (BEVs) are exposed to a wide range of environmental and operational conditions that influence their thermal behaviour. Factors such as solar radiation, ambient temperature, lighting features, and nearby heat sources can significantly impact headlamp temperatures, potentially leading to issues like condensation, material degradation, and reduced optical performance. Accurate thermal modelling using Computational Fluid Dynamics (CFD) is essential during the design phase, but its effectiveness depends heavily on the fidelity of boundary conditions, which are often based on internal combustion engine (ICE) vehicle data. This study investigates the thermal behaviour of BEV headlamps under real-world conditions, focusing on parking and charging scenarios. Temperature measurements were taken at various locations on the lens and housing of a Jaguar I-Pace using thermocouples. The results show that lighting features, particularly the high beam, generate localized hotspots on the lens. Vehicle orientation relative to the sun also affects lens temperature, with sun-facing lamps consistently hotter than shaded ones. Notably, during fast charging, headlamp temperatures increased significantly even when the lamps were off, indicating the influence of nearby active thermal systems. These findings highlight the need to incorporate BEV-specific factors—such as lighting configurations, solar exposure, charging conditions, and adjacent heat sources—into CFD boundary condition modelling. This work provides valuable insights for improving the accuracy of thermal simulations and enhancing the durability and performance of headlamps in electric vehicles.</div></div>