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VDV261 Overview

VDV 261 defines the Vehicle-to-Infrastructure Communication Protocol (V2ICP), a Value Added Service (VAS) that reuses the ISO 15118 charging stack to let an electric bus exchange operational data with depot and charge management backends. The specification standardises how the vehicle, charging station, and backend co-ordinate so that preconditioning, departure planning, and similar energy-related workflows can run without bespoke integrations.

  • Specification reference: https://knowhow.vdv.de/documents/261/

Purpose

  • Deliver a common interface that allows vehicles to tunnel HTTPS traffic to a backend through an ISO 15118 charging session (VAS 3 – InternetAccess).
  • Define the data structures, sequence, and security requirements for exchanging time-critical operational parameters such as departure targets, preconditioning requests, and charging telemetry.

Why it exists

  • Operators need a predictable way to keep vehicles, chargers, and depot systems in sync, even when components come from different vendors.
  • By reusing the existing charging link, vehicles can communicate without separate cellular modems or custom networking hardware at the depot.
  • A shared protocol simplifies testing and certification so that fleets can scale with confidence.

High-level flow

flowchart LR
    EVCC["Vehicle"]
    SECC["Charging Station"]
    VAS["ISO 15118 VAS Tunnel<br/>HTTPS over TLS"]
    Backend["CMS"]

    EVCC -- ISO 15118 (AC/DC charging) --> SECC
    SECC -- Offers VAS 3 `InternetAccess` --> EVCC
    EVCC -- Authenticates (VIN + password) --> Backend
    EVCC == HTTPS JSON payloads ==> Backend
    Backend -- Responses / Schedules --> EVCC
    SECC -- Optional OCPP telemetry --> Backend

What it covers

  • Prerequisites across vehicle (EVCC), charger (SECC), and backend: ISO 15118, IPv6 networking, certificates, TLS, HTTP, and optional OCPP hooks.
  • The detailed V2ICP message flow, including HTTP headers, authentication via VIN/password, DNS expectations, TLS profiles, TCP timeouts, and JSON payload formats.
  • Error handling guidance such as diagnostic trouble codes for misconfiguration or lost connectivity.
  • Black-box conformance test architectures that verify interoperability for EVCC, SECC, and backend implementations.
  • A formal OpenAPI schema for the /vdv endpoint that transports the time-series payload between vehicle and backend.