The Renewable Energy Sources (RES) produce a clean and an infinite power, in the same way, they generate perturbations and instability in the grid. Battery Energy Storage Systems (BESS) are the most used recently on microgrids in order to manage the integration of renewable energies to power grids and help the control system to reduce the undesirable effects such as active power fluctuation. The greater the complexity of such systems, the more tests are required, all with greater accuracy than ever before. Real-time digital simulation enables researchers to study the effects of multiple scenarios, in near-real conditions and without risk, prior to deployment in the field. In order to compare the effectiveness of energy storage system during critical situations, this paper presents the results of real-time simulation by using RT-LAB platform in order to test the response of the energy storage batteries during and after a fault on a microgrid model.