To manage an electrical network in a stationary application or in an embedded application such as hybrid or electrical vehicles, it is necessary to understand and to model the electrical behaviour of the sources on board. This paper deals with the characterization of supercapacitors as electrical power sources, in order to model them. Three equivalent electrical circuit models of supercapacitor are proposed, corresponding to different levels of modelling. The identification of these model parameters is carried out with adapted characterization tests, such as charge and discharge test at constant current and Electrochemical Impedance Spectroscopy in environmental constraints. The experimental results are compared and analysed, for many characterizations in different test conditions in terms of voltage (from 0.5 to 2.7 V), temperature (from -20 to 55 degrees C), frequency (from 50 mHz to 20 kHz) and on many supercapacitor cells of several capacitances (650 F, 1200 F and 3000 F) and from two suppliers (Maxwell and Batscap). (C) 2013 Elsevier B.V. All rights reserved.