Real-World Bidirectional EV Charging System Uses 5G, OBD-II, and OCPP

A team led by Shangqing Wang at TU Dresden has published the first real-world implementation of a user-aware bidirectional EV charging system, moving beyond simulations to a full deployment at Ostra Sport Park in Dresden. The system, built under the Mobilities for EU and DymoBat projects, combines a wireless OBD-II dongle to read vehicle battery state-of-charge before the car is even plugged in, transmitting that data over a 5G campus network to a central optimizer. A tablet-based interface lets drivers set their departure time and desired energy level, allowing the optimizer to balance individual needs with grid conditions. The entire communication stack uses the Open Charge Point Protocol (OCPP) to link the EV, charging station, user interface, and grid control center. Early data acquisition gives the optimizer a predictive edge—it can plan discharge periods when grid load is high, then re-charge in time for the user's departure.

Field tests at the Ostra Sport Park car park demonstrated significant improvements in load balancing and robust vehicle-to-grid (V2G) operation. The system successfully handled dynamic discharging requests while ensuring EVs returned to their target state-of-charge by the user's specified departure time. The researchers highlight that the multi-level communication architecture—spanning embedded hardware, 5G networking, and cloud-based optimization—provides a practical benchmark for positive energy districts and future urban e-mobility systems. While the paper focuses on infrastructure, it hints at scalability: with millions of EVs potentially acting as distributed batteries, such systems could turn parking lots into grid stability assets. The work was presented at the 2025 E-Mobility Power System Integration Symposium and published on arXiv in May 2026.