Li-ion based Electric Vehicles (EVs) are able to achieve good dynamic performance with enhanced autonomy range compared to last EVs generations. However, the announced range is often subject to important fluctuations according to the vehicle use and to the weather conditions. In order to improve the vehicle autonomy and ensure a better stability of the performance the vehicle use could be optimized. An advanced optimization requires a deep knowledge of the vehicle behavior and of the consumption influent parameters. This paper describes how a relatively simple model could fulfill these requirements and could present a good starting point for optimization actions such as eco-driving, green routing and auxiliaries' management. The presented model includes in particular an electric circuit based battery model that takes into account the diffusion phenomenon. The global vehicle model is validated using the results of a 60-drivers experiment performed with the EV on a predefined route. The variability of the energy consumption, partly due to the driver behavior, is relatively well predicted by the model and the comparison results allow us to plan favorable perspectives to use the developed model for the optimization purpose.