The batteries have been continuously for obtaining the high voltage platform and high density of energy with long lifecycle. The operating temperature of the battery cell has a significant effect on the thermal performance. This paper aims to consider the 18 650-type lithium-ion battery pack's thermal characteristics with the thermoelectric module using ferrofluid as a coolant. The experiment apparatus is test to determine the lithium-ion battery pack's temperature distributions. Effects of the relevant parameters; hot and cold side flow rates (0.03-0.05 m 3 /hr), supplied voltage through thermoelectric (8-12 V), coolant types (De-ionized water and ferrofluid), and ferrofluid concentrations (0.005%-0.015% by volume) on the battery pack's cooling performance are considered. It is found that the thermoelectric cooling system significantly affects the battery pack cooling and gives the temperature of battery below 30 C.