This article presents the results of work related to power supply system for electric go-kart. The power supply system is composed of battery cells, BMS (Battery Management System) and a DC/DC converter for some peripheral devices. During the design of the system, various possibilities of energy storage were considered, based in particular on different types of batteries. The MBD (Model-Based Design) methodology was used to develop the power supply system, consisting in the development of a simulation model of the system and the study of the space of possible solutions with the use of these models. The model of the drive system determined the energy demand to obtain the required power, torque and rotational speed for a given trajectory. Various driving scenarios were analyzed. On their example, we developed models showing the energy demand for given route. The results show the estimated driving time for various conditions. The system operating time may be shorter or extended. It depend on the driving style and the nature of the route. The developed simulation model allowed to select appropriate parameters of the power supply system and the drive system so as to meet the criteria assumed.