This paper presents different methods and approaches allowing a better energy management for Hybrid Electrical Vehicle presenting a multi-source system, in order to increase its autonomy, reduce the costs of its energy consumption and decrease pollutant emission. The main goal sought is to minimize the battery discharge allowing the vehicle to make a maximum number of cycles (repeating the same mission), while respecting constraints related to the energy system functioning and design of both sources. To do this, a fuzzy approach is proposed, and tuned using an evolutionary algorithm, to finally manage on-line the dispatching of electrical energy minimizing the consumption criterion thus increasing vehicle autonomy. To measure the quality of the on-line solution, off-line study is realized on a known mission profile and optimization based on a nonlinear modeling of the problem due to the sources characteristics is used. The problem is solved using optimization techniques which give a good global optimum in order to compare it with the battery discharge obtained on-line.