A battery thermal management system (BTMS) plays a significant role in an electric vehicle (EV)'s battery pack to avoid the adverse effect of extreme heat being generated during application. A heat pipe-based BTMS is regarded as an alternative technique to maintain an optimum working temperature of the lithium-ion batteries (LIBs) used in EVs. In this study, the heat pipe-based BTMS was designed and experimented under high input power. The battery surrogate was sandwiched with L- and I-shaped heat pipes, and heated at 30, 40, 50 and 60 W. The heat pipes' condenser sections were cooled by water at 0.0167, 0.0333 and 0.05 kg/s. Findings revealed that the designed heat pipe-based BTMS could give the maximum temperature (Tmax) below 55 °C, even at the highest input power, and provide the temperature difference (ΔT) below 5 °C. It exhibited capability to transfer more than 92.18% of the heat generated. Controlling the Tmax and ΔT within the desirable range demonstrates that the heat pipe-based BTMS is viable and effective at higher heat loads.