The core of this thesis concerns modelling, simulation and the study of the energy management system of an electric vehicle powertrain. More specifically this vehicle is a quadricycle L7e, whose name is Microlino 2.0. Thesis work is made in collaboration with Bylogix srl, a company near Turin operating as a tier 1 in automotive field. In Microlino 2.0 project, it has a development key role: design E/E (electric/electronic) architecture, supply the vehicle ECU (Electronic Control Unit) which operates both as BCM (Body Control Module) and VCU (Vehicle Control Unit) and HMIs (Human Machine Interface) cluster like screen and touchpad. The aim of this work is to create the powertrain model in order to evaluate the State Of Charge (SOC) of the battery.