Abstract: The thermal control and heat management of lithium-ion (Li-ion) batteries in high-power applications remains a challenge to be addressed before widespread commercialization. To solve the problem, micro heat pipe array (MHPA) is used to design Liion battery packs cooling system. Experiments were conducted utilizing Li-ion battery packs under open conditions with constant current of 18 A(1 C) and 36 A(2 C). The temperatures were measured with and without micro heat pipe arrays during the charge-discharge cycle. At the rates of 1 C and 2 C, the temperature results of the Li-ion battery packs validate the effectiveness of the functional heat conducting material-MHPA in lowering the temperature of the battery packs, as well as the temperature difference inside the packs, the temperature and temperature difference could be controlled within 40℃ and 5℃ respectively. Thus, they preliminarily solve the influence of temperature on battery life and capacity. Based on the experimental data, the heat in one of the 2 C working conditions was calculated, and the convection heat dissipation by MHPA reached 40% of the heat generation in the pack.