With the request to reduce gas emissions and minimize using fossil fuel, the most vehicles companies are deciding to produce clean cars like electric and hybrid vehicles, which need an important electrical power, since so many electronic features are used in order to improve the vehicle performance, this power is conditioned by the electrical energy storage system such as batteries and supercapacitors. Nowadays supercapacitors (ultracapacitors) become an attractive alternative storage device for several applications. They can be used in combination with other energy supplies like batteries.In order to understand the electrical and energetic behavior of ultracapacitor, several electric models of supercapacitors, which characterize their real behavior, have been developed.The purpose of this paper is to propose a new electrical model of supercapacitors, the degree of complexity of the model was selected in a manner that it will not penalize neither fidelity (model precision), neither accessibility (determination and measurement of the model parameters) and in order to evaluate our new model an experimental study and simulation has allowed to validate the proposed model.