The emergence of More Electric Aircraft needs to adapt their electrical architecture and their level of power generation and storage. This paper deals with the optimal sizing of battery and supercapacitor systems to match their energetic performances with the aircraft requirements. In this application, the global weight is minimized by acting on variables which are the cut-off frequency of the filter used for energy management, the discharge ratio for storage components and temperature. The optimization results, obtained with the simulated annealing method, are assessed on the whole temperature range. Finally, a relation between the cut-off frequency and temperature is determined to adjust the on-board energy management.