An electric energy supply system for an All Electric Combat Vehicle (AECV) should in an efficient manner support all subsystems which use electric energy. The subsystems may be either continuous energy consumers, such as propulsion systems, sensors and communication systems, or pulsed energy consumers, as electric guns and electric armour. These subsystems have different power and energy requirements, but must be able to share a common energy supply system, since there is not space for a separate energy supply system for each electrified application on a normal combat vehicle. This report details parts of the work with building a simulation model of an AECV energy system in MATLAB/Simulink during 2005. The developed simulation model admits a description of the subsystems in terms of electric circuit components and electric currents, concurrent with a control system which in a flexible way regulates the connection and disconnection of different subsystems. Energy sources are connected in a pre-selected priority order depending on variations in the power requirement, while different energy consumers, such as electric weapons and protection functions, are activated according to a pre-selected mission profile that can easily be replaced. Furthermore, the simulation model can emulate user controlled functions, such as the firing of an electric gun or a pulsed electromagnetic weapon.