The core idea of this project lies on the design of Intelligent Battery Modules (IBM) structures which guarantee a flexible management of the battery cells, facilitating the implementation of customized sorting algorithms to actively solve voltage unbalances. IBMs should be able to implement an active energy management by selecting the cells according to their State of Charge (SOC) to perform balancing and avoid any dissipative phenomena, ensuring an optimum energy deliver. Moreover, the temperature of each cell should be monitored allowing the implementation of customized algorithms to avoid drift phenomena. Finally, a modular structure should facilitate the integration of diverse battery chemistries, thereby optimizing the system potential. The goal is therefore to design and implement a new comprehensive concept for grid interface of BESS. The standard battery pack and power converter are replaced with the serial and parallel connection of several IBMs forming a DC/AC multilevel converter, to guarantee the correct exploitation of the energy system.