The most important problem for providing energy from Renewable Energy Sources (RES) to the electric power system is unstable and variable of the energy generated from these sources by depending on the climatic conditions. When sun is shining and a day without cloud, the more electric power can be produced with solar energy, but the amount of produced electrical energy is fluctuating continuously by depending on the climatic condition and solar irradiation. Energy storage applications can cope with the change in value resulting from the power of renewable energy systems according to climatic conditions and only day that can work as solar energy systems. The use of energy storage application is become compulsory solutions for providing more power quality to the loads by using micro grids. In this study, modelling of batteries that are component of energy storage system has been performed. In the laboratory, battery charge/discharge tests were implemented to obtain the necessary parameters for modelling studies. Graphics and results were obtained with MATLAB/M-File program by using experimental results. Experimental and modelling results compared and the accuracy of the modelling equations is given in this paper.