Energy of a Charged Conductor/Capacitor #8211; When a conductor/capacitor is charged, its potential increases from 0 to V and work is done against repulsion, between charge stored in the conductor and charge coming from the source (battery). This work is stored as electrostatic potential energy. The graph of rise of potential of the capacitor with charge is shown as figure given alongside (Q ∝ V). U = 1/2QV = 1/2CV<sup>2</sup> = Q<sup>2</sup>/2C