ChargeX Consortium proposes solution to increase reliability of electric vehicle charging

As more public chargers open nationwide, consumers should get a successful charge the first time, every time.

The Joint Office of Energy and Transportation is dedicated to creating a reliable charging experience, and new research from the National Charging Experience Consortium (ChargeX Consortium) advances that goal. Called “Recommended Practice: Seamless Retry for Electric Vehicle Charging,” the report proposes a way to automatically prevent the session from ending during the first few minutes of a charging session when the communication is established between the vehicle and the charger, taking the troubleshooting work off the consumer and instead building it into the technology between the vehicle and the charging equipment.

The ChargeX Consortium convened industry partners and national labs to create this recommendation. The concept of “seamless retry” was initiated by the EV industry, which provided standards development, system engineering, and testing. Researchers at National Renewable Energy Laboratory and Idaho National Laboratory and electric vehicle supply equipment (EVSE) businesses authored the report.

The report includes recommendations to implement the seamless retry mechanism for direct-current (DC) electric vehicle (EV) fast charging as defined by ISO 15118. Details in the report include:

• Implementation best practices, including requirements for both EVSE- and EV-side timing intervals and parameters, such as dwell time or session timeout
• Alternatives for situations when the seamless retry mechanism is not the best approach to resolving a charging session, such as loss of control pilot or overvoltage
• Recommendations for how to integrate the seamless retry mechanism into existing standards, such as ISO 15118-2 and -3, SAE J2847/2 and SAE J1772

“We are working to make charging systems more interoperable, while also taking the burden off of the consumer. This seamless retry mechanism would accomplish both,” says Sarah Hipel, acting chief technology officer, Joint Office. “This work from the ChargeX Consortium’s researchers and industry partners is yet another step in our technology-enabled approach toward building a more reliable charging network.”

The Joint Office convenes private and public stakeholders across the electric vehicle industry to advance a more connected charging ecosystem. Results include:

• Common framework enabling Universal Plug & Charge from SAE ITC and its Electric Vehicle Public Key Infrastructure (EVPKI) Consortium: Framework enables vehicles, chargers, and charging stations to speak the same language for the first time
• Research-based recommendations for improving adapter safety: The report shares findings from a Failure Mode and Effects Analysis (FMEA) conducted by the ChargeX Consortium that helps identify gaps in adapters’ performance and adherence to common safety requirements
• Unified communication protocols for electric mobility with EVerest open-source software tools: Via a partnership with the Linux Foundation (LF) Energy, the Joint Office is working to enable an interoperable foundation for innovation in EV charging
• Additional research and analysis projects like this that improve zero-emission and EV charging and refueling infrastructure for all Americans

“Seamless retry is another example of how tech-enabled solutions can directly improve the user experience, in this case by automating what can be a manual intervention,” says Gabe Klein, executive director, Joint Office. “The ChargeX Consortium continues to bring together valuable research and industry input to advance a more reliable and convenient charging network.”