The transition to electric vehicles (EVs) promises a cleaner future, but for many drivers outside the Tesla ecosystem, charging an EV on the road can still be a frustrating experience. Unlike the simple, one-tap transactions common for everyday purchases, initiating an EV charge often requires navigating a multitude of poorly designed mobile applications. This complexity is precisely what emerging standards like Plug & Charge aim to eliminate.
The Promise of Seamless EV Charging
Plug & Charge, a system built upon the international standard ISO 15118, is designed to automate the entire process of user authentication and payment at charging stations. This technology has been in development for several years and is now beginning to gain traction. Its adoption is particularly strong in Europe, where support for ISO 15118-20, the latest iteration of the standard, will become mandatory for charging infrastructure starting in 2027. In the United States, there is currently no similar regulatory mandate or timeline for ISO 15118-20 implementation.
Leading EVSE (Electric Vehicle Supply Equipment) provider and charging network operator ChargePoint has announced that its entire current hardware range now supports Plug & Charge. A growing number of other charging point operators (CPOs) are also integrating this capability into their networks. The official name uses an ampersand: “Plug & Charge.” The industry often uses the abbreviation “PnC” for brevity.
Autocharge: An Interim Solution?
While Plug & Charge matures, some industry players have implemented a precursor system known as Autocharge, which is based on the DIN Spec 70121 standard. EVgo, an early adopter of Autocharge, reports that approximately 30% of its charging sessions are now initiated using its proprietary version, Autocharge+. Similarly, charging provider Emobi is promoting its own ISO 15118-based system, branded as JustPlug.
The emergence of these different systems has led some to question whether a “standards war” is on the horizon. However, industry experts largely agree that this is not the case. Vehicles and charging stations can, and often do, support both Plug & Charge and Autocharge concurrently. Major players like ChargePoint and EVgo already offer support for both systems. It’s also worth noting that Tesla’s proprietary charging system is based on the ISO 15118-2 standard, suggesting an underlying alignment towards future interoperability.
Understanding the Underlying Standards
It is crucial to understand that both Plug & Charge and Autocharge are not standards in themselves, but rather feature sets enabled by underlying technical standards. Semih Tetik, Project Manager at CharIN (the organization driving the Plug & Charge standard), clarified the relationship:
- DIN 70121 establishes the foundational DC charging communication protocol, which is broadly supported by most DC-capable EVs.
- ISO 15118-2 builds upon this foundation, introducing advanced functionalities, including the Plug & Charge feature for automated authentication and payment.
- ISO 15118-20 further expands this framework, incorporating capabilities such as bidirectional charging (Vehicle-to-Grid or V2G) and wireless charging technologies.
The Path to Widespread Adoption
Industry experts generally view Autocharge as a transitional solution that will eventually be superseded by the more secure Plug & Charge system. However, the timeline for this transition remains uncertain, as significant work is still required to achieve widespread Plug & Charge adoption.
Arcady Sosinov, CEO of Tritium, described Autocharge as “very rudimentary.” He explained, “All you’re doing is registering the MAC address of your car with the network’s backend, and they link it to an account. But it’s insecure, and it’s sort of a hack. Autocharge has to go away, but the issue is that most vehicles on the road today are not Plug & Charge capable.”
An EVgo spokesperson confirmed their commitment to the Plug & Charge standard but highlighted the ongoing need to resolve implementation and certification complexities. “We are committed to rolling out the Plug & Charge standard once the intricacies around certification and implementation have been addressed, [but] in the meantime, we continue to support Autocharge+ as our current solution to offer seamless session initiation,” the spokesperson stated.
Juha Hytönen, Senior Director, EVs at security specialist Irdeto, noted that Autocharge was developed to address a specific, limited use case. “AutoCharge was developed to address one narrow use case. It’s great because it showcases how simple charging an EV can be, and it has proven the potential for Plug & Charge. However, AutoCharge doesn’t provide the security foundation. I think there is a place for AutoCharge for a few years until ISO 15118 is fully deployed, but Plug & Charge is eventually going to replace it,” Hytönen commented.
Overcoming Implementation Hurdles
ChargePoint is deploying Plug & Charge in both North America and Europe but acknowledges the significant challenges in scaling the technology for widespread use. Daniel Brown, Senior Director of Product Management at ChargePoint, stated, “The consumer demand for Plug & Charge is clear, but scaling access to drivers is a complex exercise in global alignment across hundreds of market players in four key areas.”
These key areas include:
- Hardware and Software Compatibility: CPOs must source charging hardware and backend software systems that are compatible with Plug & Charge.
- E-Mobility Service Providers: Companies managing user interfaces and payment processing need to coordinate with backend providers that manage the charging infrastructure.
- Vehicle Manufacturers (OEMs): Automakers must equip their vehicles with Plug & Charge capabilities and implement backend software for managing digital certificates.
- Certificate Authorities: These entities are essential for overseeing the authentication process, ensuring the trustworthiness and security of each charging session.
Security and Future Capabilities
Semih Tetik from CharIN elaborated on the security differences: “Autocharge is inherently less secure, as it relies on identifier-based mechanisms rather than cryptographic authentication. Many OEMs have already implemented ISO 15118-2 and therefore have the technical foundation to support secure Plug & Charge using PKI-based authentication. From this perspective, implementing Plug & Charge is not fundamentally complex.”
He added that while ISO 15118-20 introduces greater complexity, it represents a “long-term unifying communication protocol, capable of supporting both current and future charging use cases.” Features like V2G are driving this increased complexity, but it is accompanied by enhanced security measures, including TLS 1.3 and robust certificate management.
CharIN is actively facilitating the development and deployment of Plug & Charge through its regular Testival events. These events include interoperability testing for ISO 15118-2 and crucial Public Key Infrastructure (PKI) related tests, conducted in collaboration with industry partners, to ensure the secure and reliable operation of Plug & Charge systems.