ISO 15118: Unlocking Smart, Seamless EV Charging

Introduction As the electric vehicle (EV) industry accelerates globally, supporting technologies must evolve to deliver convenience, reliability, and security. One of the most important recent advancements is ISO 15118, an international standard that governs bi-directional digital communication between EVs and charging stations.

ISO 15118 is pivotal for enabling Vehicle-to-Grid (V2G) technology and the highly user-friendly Plug & Charge feature. With Plug & Charge, EV drivers simply plug in their vehicle, and charging starts automatically—authentication and payment happen in the background, with no cards, apps, or PINs required.

At its core, ISO 15118 defines a secure, encrypted communication process between the vehicle and the charging station, ensuring seamless authentication, billing, and energy management.

What Is the ISO 15118 Standard?

Officially titled “Road Vehicles – Vehicle to Grid Communication Interface,” ISO 15118 is developed jointly by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). It establishes an IP-based communication protocol between electric vehicles and charging infrastructure, referred to in the standard as the Supply Equipment Communication Controller (SECC) or Electric Vehicle Supply Equipment (EVSE).

The main objectives of ISO 15118 include:

• Seamless interoperability: Ensures vehicles and chargers from different manufacturers work together.
• Enhanced convenience: Enables Plug & Charge, Smart Charging, and V2G integration.
• Real-time communication: Facilitates data exchange between EVs and stations for optimized charging.

Key Capabilities:

1. Bi-directional communication: Supports V2G, enabling vehicles to both charge from and supply energy to the grid.
2. Automatic authentication: Eliminates manual steps like RFID cards or PIN codes.
3. Secure transactions: Uses advanced encryption and digital certificates to protect data.
4. Simplified driver experience: Charging begins with a single action—plugging in.

ISO 15118 is compatible with both AC and DC charging and supports both private and public charging networks.

How Plug & Charge Works

The Plug & Charge feature demonstrates ISO 15118’s consumer-focused design.

Step-by-Step Process:

1. Connection Initiated: Driver plugs in the charging cable. No additional interaction is required.
2. Digital Certificate Exchange: The vehicle shares a digital certificate, validated via a secure Public Key Infrastructure (PKI).
3. Authentication: The charging station verifies the EV with the backend Charging Point Management System (CPMS).
4. Charging Authorization: Once authenticated, the session begins automatically.
5. Energy Transfer: DC or AC power flows to the battery, with real-time communication for status updates.
6. Billing: Payment is processed automatically through the digital certificate.
7. Session Completion: Driver unplugs the cable, ending the session without extra steps.

This seamless process eliminates common frustrations like malfunctioning apps, lost RFID cards, or forgotten PINs.

Security in ISO 15118

Security is critical when financial transactions and sensitive data are involved. ISO 15118 ensures:

• Encryption: All communication is encrypted to prevent eavesdropping.
• Authentication: Both EV and charger verify each other using digital certificates.
• Data Integrity: Message authentication codes prevent undetected tampering.

Using PKI—the same technology that secures online banking—ISO 15118 guarantees that only trusted vehicles and chargers can communicate.

ISO 15118 and OCPP 2.0

While ISO 15118 governs vehicle-to-charger communication, Open Charge Point Protocol (OCPP) manages communication between the charger and the central backend system of the Charge Point Operator (CPO).

OCPP Tasks:

• User authentication
• Energy consumption tracking
• Remote start/stop commands
• Maintenance reporting

OCPP Versions:

• OCPP 1.5: Basic session control.
• OCPP 1.6: Adds Smart Charging features and scheduling.
• OCPP 2.0 / 2.0.1: Supports richer data exchange, precise load management, and integration with ISO 15118’s Plug & Charge and V2G capabilities.

Why OCPP 2.0 Matters for ISO 15118: With ISO 15118, the EV communicates the energy it requires. OCPP 2.0 allows this information to be sent to the backend, enabling optimized load management, fair energy allocation, and cost-effective grid usage.

Benefits for Stakeholders

EV Drivers:

• Seamless Plug & Charge experience
• Faster charging initiation
• Automatic, transparent billing

Charge Point Operators (CPOs):

• Improved operational efficiency
• Enhanced security and fraud prevention
• Better integration with smart grids and demand-response programs

Utility Providers:

• Accurate energy demand monitoring
• Improved load balancing
• Easier integration of renewable energy sources

Challenges in Implementation

• Hardware compatibility: Existing stations may require upgrades to support ISO 15118 and OCPP 2.0.
• Certificate management: Secure issuance, renewal, and revocation of digital certificates can be complex.
• Market fragmentation: Variations in regional adoption may affect interoperability.
• Cost: Infrastructure upgrades demand investment in both hardware and software.

The Future of ISO 15118

Widespread adoption is expected as EV demand grows:

• Global standardization: Uniform charging procedures across regions.
• Advanced V2G: EVs can return energy to the grid during peak demand.
• Dynamic pricing: Energy costs can adjust based on real-time grid conditions.
• Enhanced user experience: Seamless, fast, and secure charging.

Automakers increasingly integrate ISO 15118 into vehicles, while more CPOs upgrade infrastructure. Together with OCPP 2.0, this forms the backbone of next-generation EV charging networks.

Conclusion

ISO 15118 is transforming EV charging by simplifying authentication, securing transactions, and enabling intelligent energy management. Plug & Charge makes charging as effortless as connecting a cable, while integration with OCPP 2.0 ensures optimized energy distribution and smart grid compatibility.

As global EV adoption grows, ISO 15118 will play a central role in building a fast, secure, and user-friendly charging ecosystem, benefiting drivers, operators, and utilities alike. The future of EV charging is smarter, safer, and more connected—and ISO 15118 is driving the way.It's important to know about Google SEO to help your website rank higher in search results.