The task of the DragSailCubeSat Electrical Power System (EPS) is to provide the satellite with enough power in all mission mode. To fulfil this task the EPS uses separate battery chargers with maximum power point tracking for every of its solar arrays. The unused energy is stored in two LiFePo4 batteries which secure the satellites operation during the eclipse phase of the orbit. As distribution network a 3.3V and 5V bus are used to power the other subsystems. In addition, the EPS has to deploy the satellites antennas at the beginning of the mission. Also the subsystem is highly redundant in almost every part, securing operation even if a part fails by switching to the redundant system. These tasks renders the EPS one of the most important subsystems.