Learn how OCPP makes EV charging seamless, secure, and future-ready for a smarter charging experience.
Table of contents
What is OCPP?
The Open Charge Protocol (OCPP) is an open communication standard designed for EV charging stations to interact effortlessly with central management systems (CMS).
OCPP is crucial for interoperability between EV charging hardware and EV software providers, allowing any charger to connect with any management software globally.
History
OCPP began as an initiative by ElaadNL, a collaborative organization established by Dutch grid operators, with its first release in 2009.
In 2014, development shifted to the Open Charge Alliance (OCA), an international organization that includes utilities, charger manufacturers, software providers, and government entities.
OCPP version 1.6 was later adopted by OASIS, significantly influencing global EV charging standards in Europe and the US.
| Year | Milestone |
|---|---|
| 2009 | First version announced by ElaadNL |
| 2010 | Release of OCPP 1.2 |
| 2012 | Release of OCPP 1.5 |
| 2014 | Open Charge Alliance founded |
| 2015 | Release of OCPP 1.6 |
| 2017 | Tridens becomes OCPP 1.6J compliant |
| 2018 | Release of OCPP 2.0 |
| 2020 | Release of OCPP 2.0.1 |
| 2021 | Tridens becomes OCPP 2.0.1 compliant |
| 2025 | Release of OCPP 2.1 |
OCPP Versions
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| OCPP 1.6 | OCPP 2.0.1 | OCPP 2.1 | |
|---|---|---|---|
| Release | 2015 | 2020 | 2025 |
| Security | Basic TLS encryption, no strict authentication | Stronger encryption, certificate-based authentication, security profiles | Advanced encryption, enhanced security policies, more flexible authentication |
| Smart Charging | Load balancing, static charging profiles | Dynamic smart charging, flexible schedules, energy optimization | V2G (Vehicle-to-Grid) support, enhanced grid interaction |
| ISO 15118 (Plug & Charge) | Not supported | Supported with improved handling of certificates | Fully supports ISO 15118-20 with bidirectional charging |
| Interoperability | Medium, vendor-specific implementations | High, with structured messaging | Very high, supports modular components and renewable energy integration |
| Device Management | Limited station monitoring & control | Device Model introduced for remote diagnostics | Enhanced diagnostics, real-time telemetry, improved component handling |
| UI & User Experience | Basic session handling | On-screen messages, multi-language support | Advanced notifications, real-time cost tracking, improved reservation system |
| Billing & Payments | Simple kWh-based billing | Flexible transaction models (kWh, time-based, fixed cost) | More advanced session management, resume transactions after interruptions |
| Reservations | Basic reservation functionality | Improved reservation for fleet and network operators | Enhanced pre-booking & dynamic scheduling |
| Market Adoption | Widely used | Growing adoption | New standard |
OCPP 1.6
OCPP 1.6, released in 2015, quickly became a global standard with basic smart charging capabilities.
OCPP 1.6 has two variations:
- OCPP 1.6S: Uses SOAP technology
- OCPP 1.6J: Uses JSON technology, and it’s currently the most widely used EV charging protocol among all EV charging protocols
Key features:
- Basic smart charging & load balancing
- Remote transaction management (Start/Stop)
- Basic security, later extended with optional enhancements
- SOAP (1.6S) & JSON (1.6J) implementations
- JSON (1.6J) is the most widely adopted version
OCPP 2.0.1
OCPP 2.0.1, released in 2020, marks industry’s growing need for secure and interoperable charging solutions.
It introduces enhanced device management, robust security measures, and seamless Plug & Charge.
Key features:
- Advanced device management & detailed monitoring
- Enhanced security: certificate-based authentication & secure firmware updates
- Unified TransactionEvent messaging
- Native ISO 15118 Plug & Charge support
- WebSocket data compression for efficiency
- Multilingual real-time user interface improvements
OCPP 2.1
The newest version of OCPP, released in 2025.
Key features:
- Bidirectional charging (V2G/V2X) compliant with ISO 15118-20
- Dedicated DER control for optimal energy management
- Battery swap station integration
- Enhanced smart charging & transaction handling
- Support for prepaid, ad-hoc payments, & dynamic QR codes
Our prediction: OCPP 2.1 is the next-gen protocol. It will become more dominant within the next 2-3 years, driven by increasing regulatory requirements and industry demand for interoperability and advanced features.
In fact, OCPP protocol has features tailored toward modern requirements in the EV charging business and supports most of today’s needs.
One crucial feature of OCPP is dynamic load management (DLM), which optimizes power distribution among multiple EV chargers, preventing grid overload and ensuring efficient energy use.
Use Cases
OCPP enables essential EV charging functions:
- Authorize charging session
- Billing & payment processing
- Grid load management
- Charge point operation & monitoring
- Reservation & scheduling
- Smart charging optimization
Charging networks and station owners need to bill drivers for their electricity use and manage the chargers’ electrical load.
Smart EV Charging: Unlocking Its Full Potential
Why it matters? Chargers must be controlled through a central interface to ensure efficient operation and load balancing.
How it works? These central management systems are typically cloud-based and operate using the public internet.
How does OCPP work?
OCPP enables communication between EV charging stations and backend systems for secure, standardized, and remote-controlled charging operations.
Technical data flow
Here you can see a data flow and connections between systems involved in EV charging, including the charging station, gateway, API, and user applications:
- Charging Station: The charging station sends key OCPP commands such as
StartTransaction,StopTransaction,MeterValues, andStatusNotificationto communicate with the backend system. - Charging Gateway: Acts as an intermediary between the charging station and backend API, ensuring secure and structured data exchange.
- Charging API: Processes data from the charging station and makes it accessible to various applications.
- Web Dashboard & Mobile App: These tools allow users to monitor charging sessions, view costs, and control charging remotely.
EV charging process
When electric vehicles are charged using OCPP, the typical charging sequence is as follows:
- Reservation: Driver reserves a charger via mobile app or platform.
- Charger Hold: Charger is reserved by CMS and physical station.
- Identification & Authorization: Driver identification via RFID, NFC, QR, or Plug & Charge.
- Charging: Charger starts the charging session.
- Notifications: Driver receives updates (e.g., battery status, session end). Notifications can be set for milestones like ‘Parking Started’, ‘Charging Ended’, or ‘Battery at 90%’.
- Charging Done: Driver disconnects and secures the connector. Charging limits can be monetary (e.g., €30), time-based (1 hour), or energy-based (kWh).
- Billing: The backend system manages billing. Consumption data is sent from the charger to the CPO, who transfers it to the EMSP. The EMSP then bills the end customers.
This ensures a seamless, automated, and standardized charging experience, improving efficiency, security, and transparency for both operators and EV drivers.
How to Connect?
OCPP chargers communicate with central management systems using WebSocket or HTTP over TCP/IP.
WebSockets are preferred for secure, real-time two-way communication.
Requirements:
- Secure connection (WebSocket over TLS recommended)
- Client-server messaging per OCPP version specifications
- Certificate-based authentication for secure connectivity
- CMS endpoint configuration for real-time monitoring & remote updates
Future Outlook
Demand for OCPP adoption is high.
With OCPP at its core, the EV infrastructure industry is better equipped to deliver a seamless charging experience for users and a sustainable, interoperable network for providers.
Tridens remains fully OCPP compliant, integrating enhanced security, smart charging, Plug & Charge, and remote management capabilities into Tridens EV Charge.
