ISO 15118-2:2014

Overview

ISO 15118-2:2014 - Road vehicles - Vehicle-to-Grid Communication Interface - Part 2 - defines the network and application protocol requirements for communications between an electric vehicle (EV) and Electric Vehicle Supply Equipment (EVSE). Published as part of the ISO 15118 family (developed in conjunction with IEC), this standard specifies the V2G (Vehicle-to-Grid) communication stack used to negotiate and control energy transfer from EVSE to battery electric vehicles (BEV) and plug-in hybrid electric vehicles (PHEV). It focuses on IP-based communication between the EVCC (EV Communication Controller) and SECC (Supply Equipment Communication Controller) and on the application-layer message set needed for secure, reliable charging sessions.

Key technical topics and requirements

• Application layer message set - XML/EXI formatted messages and a defined data model to negotiate charging parameters, identification, and session control.
• Transport and network protocols - defined usage of V2GTP, TCP, TLS 1.2, and IPv6 for secure, routed communication.
• Security and certificates - XML Signatures, certificate profiles, certificate handling and revocation mechanisms (OCSP references), and TLS-based transport security.
• Data representation - use of XML with Efficient XML Interchange (EXI) for compact message encoding.
• Communication states, timing and sequencing - session setup/teardown, handshake procedures, timers, error handling and message sequencing rules.
• Layer interactions - how layer‑3 services access data link layer functions (physical/data link layers are specified in ISO 15118-3).
• Identification modes - support for External Identification Means (EIM) and Plug & Charge (PnC) scenarios.
• Normative references - integration with relevant standards (e.g., IEC 61851, IEC 62196) and IETF RFCs for IPv6, TCP, TLS and related protocols.

Practical applications and who uses the standard

• EV manufacturers and suppliers integrating secure charging communication into vehicles (EVCC).
• Charging station and EVSE vendors implementing interoperable SECC communication stacks.
• Charging network operators and service providers enabling billing, authentication and session management.
• Software developers and system integrators building V2G back-end services, security/PKI systems and certificate management.
• Test labs and certification bodies performing interoperability and conformance testing for EV/EVSE.

Adopting ISO 15118-2 enables secure, standardized plug-and-charge, optimized charging control, and future-proof integration with smart grids and vehicle energy management systems.

Related standards

• ISO 15118-1 (General information & use cases)
• ISO 15118-3 (Physical and data link layer requirements)
• IEC 61851 (EV conductive charging systems) and IEC 62196 (connectors)
• W3C EXI, XML Signature; IETF RFCs for IPv6, TLS, TCP, OCSP

Keywords: ISO 15118-2:2014, Vehicle-to-Grid, V2G communication, EVSE, EVCC, SECC, TLS, IPv6, V2GTP, XML/EXI, Plug and Charge, charging infrastructure, interoperability.