Introduction
With the global push toward sustainable mobility, the adoption of the EV (electric vehicle) is quickly becoming the norm worldwide. Various stakeholders, including governments, utility providers, automobile makers and technology vendors, invest in EV charging networks. With the rapid adoption of the EVs in the automobile industry, the Open Charge Alliance (OCA) developed OCPP (Open Charge Point Protocol), for providing a standardized communication layer between the Electric Vehicle Supply Equipment (EVSE) and the Central System management Software (CSMS). Due to the feasibility and vendor-neutrality, the OCPP is now the backbone of scalable EV infrastructure.
Overview of the EV Charging Infrastructure
EV Charging Infrastructure Comprises of Multiple Components:
- Electric Vehicle Supply Equipment (EVSE) or Charging Station: Provides electric power to the EVs
- Central System Management Software (CSMS): Monitors and controls charging operations
- Network operation: Manages connectivity and service delivery
- Utility: Supplies electrical components and energy
There are Typically Three Types of Charging:
- Level 1 (120V AC)
- Used in homes for basic charging
- It takes around 40-50 hours to fully charge an EV
- Level 2 Fast charging (240V AC)
- Found at public charging stations, workspaces, and home installations
- It takes around 4-10 hours to fully charge an EV
- Level 3 DC Fast rapid Charging (400V+ DC)
- Found at quick top-up public charging stations
- It takes around 30 minutes to an hour to fully charge an EV
Understanding OCPP (Open Charge Point Protocol)
OCPP is a free, open-source protocol. It is made and managed by the Open Charge Alliance (OCA). Charging stations use OCPP to connect with their control systems. It separates the hardware (chargers) from the software (management system) enabling innovation and choice.
A Short History of OCPP
OCPP started in 2009 with E-laad and partners like Logica and Alfen. The first version was released in 2010 to handle basic messages between chargers and software. In 2013, E-laad, Greenlots, and ESB started the Open Charge Alliance to support and manage the OCPP. Updates followed in 2012, 2015, 2018, 2020, and 2025. Each version brought new features and stronger security. OCPP is widely used to connect EV chargers with backend systems.
Key Version of OCPP
- OCPP 1.2
- First public version of OCPP
- Released in 2012
- OCPP 1.5
- An early version with basic features, e.g., Boot Notification, Data Transfer, Heartbeat, Authorize, Start/Stop Transaction, etc.
- Released in 2013
- OCPP 1.6
- Support OCPP 1.5 functionality
- Support SOAP and JSON versions
- Smart-charging, use of charging profiles, and support load balancing for better energy management
- Access to local authorization lists
- Released in 2015
- OCPP 2.0/2.0.1
- Support for extended security (i.e., security profiles, certificate handling, encryption, security logging, etc.)
- Improve smart-charging support
- Support of ISO-15118
- Released in 2018 and 2020
- OCPP 2.1
- Support OCPP 2.0.1 functionality
- Support of ISO 15118-20: bi-directional power transfer
- Enablement of bi-directional energy transfer (V2X), so the EVs also act as energy distributors
- Improvement of smart charging
- Support for local cost calculator on EV charging stations
- Introduces new authorization options: Prepaid charge card, ad-hoc payment, Dynamin QR codes
- Released in 2025
OCPP Architecture
The OCPP follows a client-server model:
- Charger Point (Client):
- The physical EV charging stations, where an electric vehicle can be charged
- It has one or more connectors
- It provides information about the charging session, status of the connector, and energy consumption value
- Central System (Server):
- It is the backend of the OCPP
- Charger-point communication with it using OCPP, for monitoring charging sessions, collecting energy consumption and billing process
Core Features of OCPP
- Authorization
- Boot Notification
- Heartbeat
- Remote Start/Stop Transaction
- Metering Data
- Firmware Update
- Diagnostics Update
- Smart Charging
OCPP Protocol Stack and Communication Flow
- OCPP typically runs over:
- Transport layer: TCP/IP
- Message protocol: WebSocket (OCPP 1.6 and newest), HTTP/HTTPs, FTP/FTPs
- Encoding: JSON, SOAP/XML (older version)
OCPP Protocol Functional Blocks
| Authorization | This functional block handles the authorization of the incoming user data before it enables the EV charging |
| Transaction | This functional block handles the starting or stopping of the charging session. |
| Remote Access | This functional block handles incoming message requests from the CSMS and performs accordingly. |
| Metering | This functional block is used to measure meter values, for updating current values in periodic or clock-aligned timing ways. |
| Local Authorization | This functionality block is used to authorize the user locally without verifying from the CSMS. |
| Firmware Management | This functionality block is used to handle firmware updates from the CSMS or update diagnostic data to CSMS for resolving issues. |
| Smart Charging | This functionality block is handling the current/power distribution of the charging sessions. |
| Data Transfer | This functionality block is used to handle the custom messages added by third-party OCPP providers. |
| Security | This functionality block is used to handle the security part of the data communications in OCPP. |
Case Study on OCPP PROTOCOL
- Case Study 1: Amsterdam Citywide Rollout
- Over 1000 EVSE units installed across the city
- OCPP 1.6J is used for all units
- Allows central control and smart load-balancing
- Helps reduce energy spikes during peak use
- Case Study 2: California OCPP2.0.1 Pilot
- OCPP 2.0.1, enables Plug & Charge feature
- Plug & Charge speeds up user sessions
- Real-time data supports better monitoring
- Helps track charger use and grid impact
- Case Study 3: OCPP Use in India
- India’s Ministry of Power and the Bureau of Energy Efficiency (BEE) require OCPP in public chargers
- OCPP supports many charger brands. (like ABB and Delta, etc.)
- Used by large networks like Tata Power and EESL
- Cities like Pune and Bengaluru test smart-charging and V2G
Benefits of Using OCPP
- Technical Benefits
- Modularity: Easily add new features without hardware changes
- Works with many brands: No need to stick with a single vendor. Chargers from different makers can talk to the same system
- Remote Access: Start or stop charging, check use, and fix problems without being on-site
- Smart Charging: Adjust charging based on grid load and time; also helps balance power use
- Real-time data: Get updates on energy use, session time, and grid status
- Flexible setup: Add custom messages while keeping core features working
- Strategic Benefits
- Grow with your network: Add new chargers without changing the setup. Used in city and country-wide systems
- More Flexible pricing: Set prices by time, demand, or user-type
- Lower costs: Less manual work; Use of pricing tools to plan and earn more
- Better service: Lets drivers find, use, and pay through apps with more choice
- Ready for what is next: Updates keep it useful as the tech changes
Building OCPP-Compliant EV Charging Solutions at einfochips
The eInfochips team has been integrally involved in developing OCPP-compliant EV chargers, projects that are helping drive the future of electric mobility. At eInfochips, we offer end-to-end solutions, from designing control boards and power systems to building firmware and software that enables secure, reliable communication with central systems.
On the software side, our team builds complete OCPP stacks that support remote charging control, live status updates, smart charging, secure firmware updates, and secure communication with the CSMS. On the hardware side, we design control boards, power electronics and communications modules and ensure all components meet performance and security standards.
By offering full product development, it is not just isolated pieces; eInfochips helps OEMs and charger manufacturers reduce time-to-market and helps with tested, future-ready solutions.
Conclusion
The OCPP is key to building smart and reliable EV charging networks. Its open design helps it grow with new tech and rules. By keeping hardware and software separate, OCPP makes it easier to add features and manage updates. It also supports smart-charging and string security. Ensuring EVSE compliance with OCPP standards helps operators maintain consistency and interoperability across devices. Using OCPP helps operators run their networks more efficiently. It can reduce costs and improve the charging experience for users. As OCPP 2.0.1/2.1 expands, it will help more cities and companies support electric vehicles. It is a smart choice for anyone planning the future of transportation.
Know More: Automotive Engineering
