Interoperability: the backbone of any thriving EV charging network.
Without it, we’d be looking at a patchwork of systems struggling to talk to each other. And that’s not the kind of future anyone wants to plug into.
That’s where open standards come in. Designed to eliminate silos and future-proof infrastructure, they’re essential for scaling EV charging networks smartly and sustainably. Among them, the Open Charge Point Protocol (OCPP) stands out as the go-to framework for enabling communication between charging stations and backend systems.
In this article, we’ll break down OCPP’s role in the eMobility ecosystem and unpack the differences between its key versions: 1.6, 2.0, and 2.0.1, so you can better understand where the industry’s headed and what it means for your business or tech stack.
What is the Open Charge Point Protocol (OCPP)?
The Open Charge Point Protocol (OCPP) has been developed by the Open Charge Alliance (OCA), a consortium of electric vehicle infrastructure providers, automakers, utilities, and other stakeholders. OCPP is an EV charging communication protocol used by charging stations and electric vehicle service providers (EVSPs). It enables two-way communication between the EVSE (Electric Vehicle Supply Equipment) and Charging Point Operators (CPOs), allowing for real-time monitoring and control of charging sessions.
OCPP is an open standard, meaning anyone can develop applications that use it. However, it is not a mandatory industry requirement—while the OCA highly recommends its use, EVSE manufacturers are not obligated to produce OCPP-compliant hardware.
In terms of its role in the EV charging ecosystem, understanding OCPP’s placement is crucial. OCPP acts as the communication syntax connecting the Charging Station Management System (CSMS)—used by CPOs to control their networks—with the physical charging stations.
Key operations covered by OCPP include:
- Authorization of the charging session: Identifies the EV driver and initiates or terminates the session.
- Billing information: Transfers charging event data to the backend system for user billing.
- Charger reservation.
- Real-time data transfer to CSMS: Enables CPOs to monitor station statuses (e.g., in-use, faulted).
- Remote charging station control.
- Issue recognition and alerts.
Versions and evolution of the Open Charge Point Protocol
Over time, the Open Charge Point Protocol (OCPP) has evolved to support new technical capabilities, stronger security, and better compatibility with modern charging infrastructure. While multiple versions exist, the most widely implemented today is OCPP 1.6, with OCPP 2.0.1 being the most current and feature-rich version. The following sections outline the key differences and improvements introduced in each.
OCPP 1.6
Released as a major step forward from version 1.5 (now largely obsolete), OCPP 1.6 added a wide range of enhancements that made it the de facto industry standard for several years. Below is a summary of the most notable features and improvements introduced in this version.
Some of the notable improvements in OCPP 1.6 include:
- Smart Charging functionality was added.
- A binding to JSON over WebSocket was introduced as a transport protocol, reducing data usage and enabling communication through NAT routers.
- Extra statuses were added to the ChargePointStatus enumeration, offering more insight into station status.
- Changes to the structure of MeterValues.req to remove XML attributes, which supports JSON compatibility.
- New measurands in the enumeration allowed for more detailed station data (e.g., EV State of Charge).
- The TriggerMessage function enabled the central system to request data from the charge point.
- A new Pending status was added to the RegistrationStatus enumeration used in BootNotification.conf.
- Improved configuration keys, giving CPOs clearer guidelines for setup.
- Messages and configuration keys were split into profiles for gradual or partial implementation.
- Various ambiguities were clarified, including connector numbering and request/response handling.
(Please note: this extract comes from the OCPP 1.6 documentation, available in full from the Open Charge Alliance.)
OCPP 2.0 and OCPP 2.0.1
OCPP 2.0 was introduced in April 2018. However, certain issues were later discovered—some significant enough to require backward-incompatible changes. For example, adjustments like increasing the security certificate length couldn’t be resolved by documentation tweaks alone. As a result, OCPP 2.0.1 was released and is now the version recommended by the Open Charge Alliance for use in production environments.
As the OCPP standard evolves, it’s essential for charging station operators and manufacturers to stay updated with the latest versions. Doing so ensures compatibility with the latest CSMS software and access to new OCPP features.
Key enhancements in OCPP 2.0 and 2.0.1
Compared to version 1.6, these newer versions introduced several impactful changes:
- Support for ISO 15118, enabling features such as Plug and Charge.
- Complete removal of SOAP in favor of JSON over WebSocket, simplifying communication protocols.
- Significant upgrades to security mechanisms, addressing previous vulnerabilities.
- Device management and monitoring replaced older Status Notifications for improved infrastructure control.
- Enhanced transaction handling to support more complex and larger-scale EV charging networks.
The official OCPP documentation consists of 7 parts:
- Introduction
- Architecture and topology
- Specification and Appendices
- Schemas
- JSON over WebSockets implementation guide
- Certification profiles
- Test cases
Building smarter, scalable EV charging networks with OCPP
As EV adoption surges, seamless communication between charging stations and backend systems becomes a foundation, not a feature. The Open Charge Point Protocol (OCPP) offers exactly that: a standardized, future-proof way to ensure your infrastructure can grow, adapt, and stay secure.
Whether you’re deploying your first charging station or managing a growing infrastructure, aligning with the latest OCPP version ensures you’re staying ahead.
FAQs about the Open Charge Point Protocol
What is OCPP, and why is it important?
OCPP is an open-source protocol for EV charging stations that ensures different hardware and backend systems can work together seamlessly. It improves interoperability, scalability, and network management for charging station operators.
What’s the difference between OCPP 2.0 and 2.0.1?
OCPP 2.0.1 was released to fix limitations and security concerns in 2.0. It includes necessary updates that are not backward-compatible, and is now the recommended version by the Open Charge Alliance.
Is OCPP mandatory for EV charging stations?
No. OCPP is a recommended but not mandatory standard. Manufacturers and CPOs are encouraged to adopt it for greater interoperability and flexibility.
Does OCPP support Plug and Charge?
Yes, starting from OCPP 2.0, the protocol includes support for ISO 15118, which enables Plug and Charge capabilities, allowing EVs to automatically identify themselves and begin charging without manual authorization.