Monitoring the Use of Energy Stored in an Electric Vehicle

A method for monitoring electric energy use stored in an electric vehicle storage device, wherein the quantity of electric energy discharged from the energy storage device and the existing charging connection state to a charging point are monitored, and the quantity of energy fed back from the energy storage device by a charging point is determined in that the quantity of energy discharged from the energy storage device is monitored when the electric vehicle is connected to a charging point. A system includes an electric vehicle that can be charged in a bidirectional manner and includes a vehicle electricity meter to measure the electric energy discharged from the energy storage, a charging point for bidirectional charging, and an external cost-calculating entity that receives information on energy quantities passing through the vehicle electricity meter and charging connection states and calculates energy quantity passing through the meter based on usage type.