The task of the DragSailCubeSat Electrical Power System (EPS) is to provide the satellite with enough power in all mission modes.
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 satellite operation during the eclipse phase of the orbit. For power distribution a 3.3V and 5V bus are used to power the other subsystems.
In addition, the EPS has to deploy the satellite antennas at the beginning of the mission. Also the EPS has to provide enough power to deploy the TFSC and the DragSail during the mission.
Also the subsystem is highly redundant in almost every part, securing operation even if a parts of it fails by switching to a redundant system. These tasks makes the EPS one of the most important subsystems.