ISO 15118 (Plug & Charge)
Family of standards for high-level communication between an electric vehicle (EV) and a charging station (EVSE), enabling certificate-based "Plug & Charge" and advanced charging control (including bidirectional charging in newer editions).
Technical Details
ISO 15118 enables TLS-encrypted communication and digital certificate handling for automated authorization and contract-based charging. It builds on foundational charging requirements (e.g., IEC 61851-1) and can exchange richer session data (e.g., charging limits and state-of-charge) to support smarter charging and V2G/V2X roadmaps. In real deployments it is commonly paired with OCPP on the EVSE-to-backend side.
Fleet Applications
Removes manual authorization steps for drivers in depots: vehicles can authenticate automatically when plugged in. Improves smart charging decisions with richer vehicle signals and forms the technical foundation for bidirectional charging programs; for e-bus operations it is also a prerequisite for VDV 261 value-added-service workflows.
Related Terms
Vehicle-to-Grid (V2G)
Bidirectional charging technology that enables electric vehicles to return digitally managed energy from their batteries back to the power grid during peak demand periods.
Smart Charging
Intelligent management of EV charging sessions to optimize energy consumption based on grid constraints, energy prices, and vehicle schedule requirements.
OCPP (Open Charge Point Protocol)
Global open application standard for communication between EV charging stations and a central management system (CSMS).
OCPP 2.0.1
Version 2.0.1 of the Open Charge Point Protocol (OCPP) that standardizes communication between charging stations and a Charging Station Management System (CSMS).
Plug & Charge (PnC)
Certificate-based EV charging where authorization happens automatically when the vehicle is plugged in—without RFID cards or mobile apps.
Contract Certificate (ISO 15118)
A digital certificate stored in the EV that enables contract-based authorization and billing for Plug & Charge sessions.
Bidirectional Power Transfer (BPT)
ISO 15118 concept for charging and discharging where an EV and EVSE coordinate power flow in both directions (V2G/V2B), not just charging.
BPT Channel (Unified vs Separated)
ISO 15118-20 parameter that describes whether bidirectional energy flow uses one shared channel (Unified) or two dedicated channels (Separated) for opposite directions.
Generator Mode (Grid-Following vs Grid-Forming)
ISO 15118-20 BPT parameter describing the inverter behavior during discharge: following the grid voltage/frequency (grid-following) or actively forming them (grid-forming).
Islanding Detection (Active vs Passive)
Techniques to detect an unintentional “island” where a site keeps energizing a local grid segment after it is disconnected from the main grid.
Bidirectional Charging
Charging that allows energy to flow both into the vehicle and back out to a building or the grid.
AFIR (Alternative Fuels Infrastructure Regulation)
EU regulation that sets binding targets for the rollout and accessibility of alternative fuels infrastructure, including EV charging.
VDV 261 (Dispositive Backend via ISO 15118 VAS)
VDV recommendation that extends ISO 15118 (Ed. 1) for e-bus operations by defining how an e-bus connects to a dispatching (“dispositive”) backend to exchange preparation parameters such as preconditioning.
V2ICP (Vehicle to Infrastructure Communication Protocol)
A VDV 261-defined protocol for exchanging operational parameters between an e-bus and a backend system via ISO 15118 Value Added Services.
ISO 15118 VAS “InternetAccess” (ServiceID 3)
ISO 15118 Value Added Service that allows the EV and EVSE to use standard internet protocols (e.g., HTTP/HTTPS) during a charging session.