Future-proof charging standards with ISO 15118

To accelerate the adoption of electric mobility, both technologically and politically, it is essential to ensure seamless communication between electric vehicles and charging infrastructure. This is where ISO 15118 comes into play: a communication interface and family of standards that enables interoperability between vehicles and charging stations.

What ISO 15118 is all about?  Which electric cars are supported by the standard? What technology is behind it? What does Plug & Charge (PnC) mean? You can find out all this in the following guide. 

The ISO 15118 standard on the one hand includes the standard communication to the vehicle via a PWM (standardised in IEC 61851-1), as it is integrated in every AC charging system today and which can only transmit rudimentary information. In addition to that, ISO 15118 also enables extensive communication via Powerline Communication (PLC) to the vehicle.

Modern electric cars mean that there is an extensive exchange of information that needs to be managed. To ensure this, the electric car industry has agreed to implement certain standards that make functions such as bidirectional charging (V2H & V2G) and the Plug & Charge method (PnC) as well as communication between the electric car and the charging station possible

Drive your e-car to the charging station, connect the car and the charging station with the cable: and you're done. Simply put, this is what is behind the new PnC function according to ISO 15118, which makes charging easy. 

Using the ISO and the PnC method, an easy-to-use information exchange is created between the electric car and the charging station. Direct communication between the vehicle and the charging station means that neither the charging card (RFID chip cards) nor the app or QR code are needed as an intermediary and become obsolete, as the software behind them controls the entire process. ISO 15118 creates a uniform communicative standard, which greatly simplifies the identification of the e-car at the charging station and enables uncomplicated charging. 

After a short registration of personal data, the electric car, the vehicle owner and the payment method are verified. In future, the electric car will be able to connect to the charging station independently using digital signatures and certificates after the electric car and charging station are connected with a charging cable. Charging is carried out automatically and the payment process is completed without further intervention. 

At present, several vehicle models from the Volkswagen Group are already equipped for a PnC charging process at charging stations. With the decision to adopt ISO 15118, this smart charging function is expected to be used as a standardised method from 2025. 

Bidirectional charging offers significant potential and numerous benefits across a wide range of applications and use cases. These range from increasing self-consumption and energy independence in the private sector (Vehicle-to-Home, V2H) to providing and using balancing power and supplying local communities in the event of a power outage (Vehicle-to-Grid, V2G).

On the one hand, this procedure works for V2H, whereby the unused electricity can be fed back into the power grid via the wallbox of the residential building. In this way, the private demand in the home can be partially covered. Vehicles with increased battery charging capacity could thus cover the demand for the entire household for several days. 

The V2G method is also to be used in the future. Here, surplus electricity is transferred from the vehicle to the entire power grid. During periods of high load, this form of bidirectional charging would ensure that the electricity grid is relieved. In the future, electric car drivers could even be financially rewarded for implementing this variant of bidirectional charging. This will make driving an electric car more and more attractive from a financial point of view.