With the development of wind and solar energy, more local governments prefer to invest an environmental-friendly power system combining wind and solar energy especially for rural areas. Researchers use different softwares such as Homer and Matlab to achieve capacity optimization for a hybrid wind/solar/battery power system. The Kinetic Battery Model (KBM) is introduced in this article and is applied as a battery model in the combined system. Achieved results are compared and analyzed with a similar power system model which has no such a specific battery model part.