Switched Reluctance Motors (SRMs) have some advantages such as simple and robust structure, low manufacturing cost, and so on. Moreover, SRMs can drive in high speed region and high temperature condition. These advantages are suited for the automobile auxiliary motors. However, in SRMs driven by voltage single pulse drive, it is difficult to achieve the demanded performances such as torque and efficiency because the output current is not controlled. Especially, the output current is strongly decreased by the back electromotive force in the high speed condition and low voltage source for automotive auxiliary motors. The output current depends on excitation angles, number of turns and motor structure. Therefore, these parameters should be optimized to achieve high motor performances in motor design. However, the method by using FEA requires enormous calculation time and effort. In this research, a novel design method which simply optimizes these parameters by using mathematical formulas is proposed.