In this article, the authors propose an approach to the problem of the power management in transport applications. The mobile experimental platform ECCE is a series hybrid vehicle which currently has three sources of energy: two thermal machines each coupled with an alternator and a lead-acid battery pack of nominal voltage 540V. The alternators are interconnected with the DC-link by means of the rectifiers. Our contribution is focused on studying the energy coupling between this battery pack and that of supercapacitors in order to find the best compromise between dimensions of the electric power devices, the efficiency mobile energy storing devices, the energy exchanges, and the capacity of exchange of electric power. The supercapacitors module consists of a pack of 108 cells and can supply a maximum of 270V. The main objective is to be able to provide a power of 216kW by supercapacitor module to the DC-link for 20 seconds.