Abstract: The lithium fluorocarbon battery, as a representative of new generation light battery with high specific energy and safe reliability, is a best choice for the primary power source supporting Mars’ explorations. In view of a large amount of reaction heat released in the discharge process of the lithium fluorocarbon batteries, there will be a significant heating effect, so the related thermal properties such as the specific heat capacity and the calorific value are to be considered. A method of using the accelerating rate calorimeter (ARC) device is proposed to determine the specific heat capacity and the calorific value of the soft package lithium fluorocarbon battery. The specific heat capacity and the calorific value at different states of charges are measured, with values and deviation not veyond the engineering allowance. The research presults can be used in the application of the lithium fluorocarbon batteries, and more engineering applications of the high specific energy primary battery are expected in the deep space probing.