OCPP Explained: Why It Matters When Choosing an EV Charger Supplier

Ask any charge point operator what their biggest procurement regret is, and you will usually hear the same story: a fleet of chargers that only work with one vendor's software. The way to avoid that story is a four-letter acronym. OCPP — the Open Charge Point Protocol — is the single most important interoperability standard in EV charging, and understanding it before you place an order can save your business from being locked into an ecosystem you don't control.

This guide explains what OCPP actually does, how the versions differ, and — most importantly for importers, distributors, and fleet buyers — how to verify that the smart chargers you are sourcing genuinely implement it. If you are newer to EV charging infrastructure generally, our charging standards guide covers the connector and hardware side of the picture.

What Is OCPP?

OCPP is an open communication protocol maintained by the Open Charge Alliance (OCA), an industry consortium of charging station manufacturers, network operators, and software vendors. It defines how a charging station talks to a backend system — technically called a Charging Station Management System, or CSMS.

"Open" is the operative word. Because the specification is publicly available and vendor-neutral, an OCPP-compliant charger from any manufacturer can connect to any OCPP-compliant management platform. The charger speaks a common language over the internet: reporting its status, accepting commands, streaming meter readings, requesting firmware updates, and so on.

Think of it like the relationship between a printer and your computer. Printers work across Windows, macOS, and Linux because they share standard page-description languages. Without that standard, every printer would need proprietary software from its maker, and switching computers would mean throwing away your printer. OCPP plays exactly this role between charging hardware and charging software.

What OCPP Actually Does: The Feature Set Behind the Acronym

When a charger is connected to a CSMS over OCPP, the operator gains a set of capabilities that define modern charging management:

• Remote monitoring and diagnostics. Heartbeats, status notifications, and error reports flow to the backend, so a broken charger is noticed before a customer complains — and often fixed remotely.
• Remote start/stop and authorization. RFID cards, app-based sessions, and backend-authorised charging all run through the protocol. This is what enables public networks and workplace charging with access control.
• Meter values and transaction data. The charger reports energy consumption per session in structured form, enabling billing, load reporting, and energy accounting without vendor-specific metering hardware.
• Smart charging and load management. The CSMS can push charging profiles and power limits to each charger — the foundation of dynamic load balancing across multiple chargers on one site, time-of-use optimisation, and grid-service participation.
• Firmware and configuration updates. Over-the-air updates and remote parameter changes keep fleets current without site visits.
• Reservation and tariff management (version-dependent), letting operators expose pricing structures through the charger itself.

OCPP 1.6 vs 2.0.1: What B2B Buyers Need to Know

You will encounter two versions in the market today, and the difference is a common point of confusion.

	OCPP 1.6	OCPP 2.0.1
Status	Most widely deployed version worldwide	Current version, adopted in newer deployments
Transport	SOAP (XML) or JSON over WebSocket	JSON over WebSocket only
Smart charging	Charging profiles, basic load management	Refined profiles, better transaction-based control
Security	Basic authentication; TLS optional	Security profiles with TLS, certificate management
ISO 15118 support	Not designed for it	Native support for plug & charge
Device management	Limited variable reporting	Rich component/variable model

Practical guidance: OCPP 1.6 remains the safe commercial default. The overwhelming majority of installed CSMS platforms support it natively, and it covers everything a typical AC charging business needs — remote control, metering, smart charging, and basic security. OCPP 2.0.1 matters when your roadmap includes plug & charge (ISO 15118), stricter security requirements, or large-scale device management. If your platform or customer specification calls for 2.0.1, verify the charger's implementation has been interoperability-tested — 2.0.1's extra surface area leaves more room for partial implementations.

One more distinction worth knowing: OCPP-S vs OCPP-J. The "S" variant uses SOAP/XML, the "J" variant uses JSON over WebSocket. OCPP-J is lighter, friendlier to cellular connections, and the standard choice for new deployments. If a supplier says "OCPP 1.6" without specifying, ask whether it is the JSON variant — and confirm your CSMS matches.

Why OCPP Matters Commercially: The Lock-In Question

The protocol question is ultimately a business question. Here is what is at stake for B2B buyers:

1. Software independence. A non-OCPP charger binds you to its manufacturer's platform — pricing, features, uptime, and roadmap all controlled by one vendor. With OCPP, you can switch CSMS providers while keeping every charger in the field.
2. Tender eligibility. Public charging tenders and many workplace programs specify OCPP compliance as a hard requirement. Non-compliant stock is effectively unsellable into those channels.
3. Asset value. Interoperable chargers hold resale value; proprietary ones do not. If your customer's network folds or re-platforms, OCPP chargers move with them.
4. Feature velocity. The smart-charging and energy-management features your customers will demand over the next five years are being built into CSMS platforms. OCPP is the pipe those features flow through. No protocol, no roadmap.

How to Verify Real OCPP Compliance Before You Order

"OCPP supported" on a spec sheet ranges in meaning from "fully tested against multiple platforms" to "we have an experimental branch." When auditing EV charger suppliers, use this verification sequence:

1. Ask for specifics: which version (1.6 or 2.0.1), which transport (JSON or SOAP), and which security profile is implemented. A supplier who cannot answer precisely has not tested thoroughly.
2. Request interop evidence. The Open Charge Alliance operates certification and interop testing programs. Ask which OCA certification the product holds, or which third-party CSMS platforms it has been tested against, and request the documentation. Genuine compliance comes with paperwork — the same principle we cover in our certifications guide.
3. Run your own interop trial. Connect a sample unit to an independent, standards-compliant CSMS before committing to volume. Open-source options such as SteVe make this test free. Verify registration, heartbeat, remote start/stop, meter values, and charging profile acceptance.
4. Test the security profile. If the deployment is commercial, confirm TLS-secured communication and proper authentication rather than unencrypted traffic.
5. Check smart charging behavior end-to-end. Push a charging profile from the CSMS and confirm the charger actually limits power. Partial stacks often implement monitoring but not control — precisely the half you paid for.

Common Pitfalls to Avoid

• Proprietary "OCPP-compatible" stacks. Some implementations speak OCPP to the vendor's own backend but add proprietary extensions required for full function. Insist on standard OCPP behavior with a third-party CSMS as the acceptance test.
• Version mismatch with your platform. A charger implementing only OCPP 1.6 SOAP cannot join a JSON-only platform, and vice versa. Match versions and transports explicitly in the purchase agreement.
• Assuming smart charging works because the logo does. Charging-profile support is where partial implementations most often fail. Test it, don't assume it.
• Ignoring security profiles. Unsecured OCPP traffic is tamper-prone. For anything beyond private pilot deployments, require at least TLS with authentication.

The Bottom Line

OCPP is what separates a commodity charger from a network-ready commercial asset. For importers and distributors, it is also a screening tool: a supplier who can discuss versions, transports, security profiles, and interop testing fluently is one who has invested in getting the details right — a signal that usually extends to hardware quality as well. KinHar Energy's wall-mounted charger line supports OCPP 1.6, and our team provides protocol documentation and sample-unit interop testing for qualified B2B buyers. Contact us for specifications and OEM options.

Frequently Asked Questions

What is OCPP in EV charging?

OCPP (Open Charge Point Protocol) is an open communication protocol that connects EV charging stations to central management systems (CSMS). It lets operators remotely monitor chargers, start and stop sessions, apply smart charging schedules, collect meter data, and push firmware updates — regardless of which company made the charger or the platform.

Is OCPP mandatory for EV chargers?

No. OCPP is a de facto industry standard, not a legal requirement. However, most public charging networks, tender specifications, and workplace charging programs require OCPP compliance, so chargers without it are effectively locked out of the commercial market. For private home charging, OCPP is usually unnecessary.

What is the difference between OCPP 1.6 and OCPP 2.0.1?

OCPP 1.6 is the most widely deployed version and covers remote management, smart charging profiles, and meter data. OCPP 2.0.1 adds a cleaner device model, better transaction handling, improved security with TLS and certificate management, device management tools, and native support for ISO 15118 plug-and-charge. Most commercial networks today still run 1.6, while new deployments increasingly specify 2.0.1.

What is the difference between OCPP-S and OCPP-J?

OCPP-S uses SOAP (XML web services) and is the older transport used mainly with OCPP 1.5 and early 1.6 deployments. OCPP-J uses JSON over WebSocket, is lighter, works better on cellular connections, and is the standard transport for new 1.6 and all 2.0.1 implementations. When sourcing, confirm the charger supports OCPP-J (JSON) unless you are integrating with a legacy SOAP platform.

How can I test if a charger is really OCPP-compliant?

The most reliable test is an interoperability trial: connect the charger to an independent, standards-compliant CSMS (several open-source options exist, such as SteVe) and verify it registers, responds to remote commands, reports meter values, and accepts smart charging profiles. Also ask the supplier which OCA certification or interop testing they have completed and request the test report.