Fuel cell applications become increasingly attractive. Therefore, comprehensive models, simulation software and analysis tools are required to characterize fuel cell behavior. This paper introduces a model capable of representing the static and dynamic (dynastatic) behavior of PEM fuel cells. The model approximates the theoretical current-voltage description with an equivalent electric circuit. The parameter values of the model are found by analyzing small-signal measurement results from electrochemical impedance spectroscopy, together with the steady-state electric characteristic and large-signal behavior from step-response measurements. Because the modeling approach is completely based on measurements on the fuel cell electric output terminals, electrochemical aspects like temperature dependency, charge double layer and adsorption effects are implicitly covered. (C) 2007 Elsevier B.V. All rights reserved.