This paper analyzes the impact of the charge of EVs(Electrical Vehicles) on a power grid. In order to simulate the behavior of the EV charging on the grid a model of its battery has been found (EV’s charging curve). As the way of the EV is charged from the grid affects critically to the voltage levels and to the saturation of the lines two modalities of charge are presented: not-controlled charge and controlled charge. Finally,the simulations have been performed from two points of view:deterministic analysis and probabilistic analysis.