Smart Charging is an optimized concept for charging the batteries ofelectric vehicles. In Smart Charging, excess energy is stored in home storage or in batteries of electric cars and delivered to the Smart Grid
or to the end users or the electric vehicles, depending on the demand. The concept of smart charging is standardized by ISO under ISO 15118. This concept is about plug-and-charge and communication between the charging station and the electric vehicle. Communication involves the transmission of important charging parameters such as charging capacity, charging time, energy costs and billing methods. With smart charging, electric vehicles are charged when energy is cheap. Communication between the charging station and the provider 's central system is supported by the Open Charge Point Protocol (OCPP). With this protocol, it is possible to connect any central system of a Charge Point Operator (CPO) to any charging point
. Smart Charging includes load management and uses the Open Smart Charging Protocol (OSCP) to determine the short- and medium-term energy demand from the consumption values. To prevent overloading of the charging stations and the energy supply network, the OSCP protocol works with energy budgets that are allocated to individual consumers. Based on this budgeting, the charge station operators can adjust the charging profiles at the electric vehicles to the available charging capacity. Another concept of smart charging is Vehicle to Grid (V2G). In this concept, the battery of the electric vehicle is integrated into the smart grid as a storage battery. The battery management system works with bidirectional energy exchange and feeds the energy stored in the car battery back into the smart grid by means of regeneration when required. This application is technically feasible, but is not yet supported by electric vehicles and charging stations.