This paper treats an experimental study of the electrical and the thermal behavior of supercapacitors for power electronics and transportation applications. In this study, the charge and discharge of supercapacitors have been characterized by taking into account the temperature variations of the device and its environment. Thermal dependence of supercapacitor serial resistance and capacitance is determined experimentally. An equivalent circuit is proposed to describe the electrical and the thermal behavior of the supercapacitors. The equivalent circuit is implemented in Saber and Spice software for simulations. Experimental and simulation results are presented, analyzed and compared. (C) 2003 Elsevier Science B.V. All rights reserved.