In the stand-alone PV, the energy is generated only by the PV panels. Therefore, during the night or in periods with low solar radiation, it is essential to put a battery bank to store the captured energy to ensure power supply. To highlight the physical phenomena that govern the operation of the storage system, we proposed in this paper to study the battery modeling. This work is devoted to the modeling and simulation under the Matlab / Simulink environment of two electric battery models; Namely the CIEMAT model (Centro de Investigaciones Energéticas, Mediomientales y Technologicas) and the simplified electric model PSpice. In order to verify the validity of these mathematical models, the results of the numerical simulation are compared with the experimental data of the solar Varta battery.