What is OCPP?
- Pekka Tiainen
- May 25
- 5 min read
These days, there's a lot of talk about OCPP. But what exactly is OCPP? What does it mean and why should you care?
This summer-themed article is split into three sections, each diving deeper into the world of OCPP. The first section covers the basics, the second gets into the technical details, and the third explores the importance of openness in charging systems. You can stop after the first part if you like, as it already contains key insights.
Openness is not just a choice for us. It is a principle. Wattery has always been, and will always be, on the side of openness.
OCPP Basics: What It Is and Why It Matters
"The main reason to use OCPP is risk management."
When people talk about smart charging systems, they usually mean systems that can be read and controlled remotely. This requires internet connectivity and often a connection to a charging operator. That connection might rely on the charger manufacturer’s own solution or a widely used communication standard known as OCPP. Remote management makes charging easier by automating billing, managing users, and resolving faults.
OCPP stands for Open Charge Point Protocol. The word “open” means the specifications are publicly available, allowing anyone to implement a compatible charger or backend system. This includes companies like Wattery and DIY projects such as Home Assistant.
The biggest advantage of OCPP is risk management. If part of the system stops working or a vendor exits the market, you can replace the broken part without being locked in, whether it’s a charger or a backend platform.
But not all OCPP systems are equal. There are pitfalls, and choosing a device that Wattery has approved reduces the chances of things going wrong.
Ready to set sail for deeper waters? Let’s go.
OCPP Versions, Architecture, and Load balancing
The two most common OCPP versions are 1.6 and 2.0.1. Of these, 1.6 is still the most widely used, and it’s also Wattery’s primary version. Version 2.0.1 is slowly gaining ground and brings new features like support for the ISO 15118 standard, which enables plug and charge, bidirectional charging (V2G), and other advanced functions. Some of these features can be partially used with version 1.6, but with limitations.
OCPP is modular. Every system includes the “Core” module, which ensures compatibility with basic functions like measurements, user data, and charging session management. On top of this, you can build a simple system that handles user identification and charging start. Billing happens on the backend, outside of OCPP itself.
Additional modules unlock more features:
Firmware Management, for software updates
Local Auth List Management, for local user access
Remote Trigger, to send commands to the charger
Reservation, to book a charging spot
Smart Charging, for load balancing
In most systems with more than a couple of charge points, like housing associations or office buildings, load balancing is essential. Without support for Smart Charging, the charger’s power cannot be controlled by third-party systems. This forces you to use the manufacturer’s own solution, which may be local or cloud-based, limiting hardware choices and tying you to a single vendor. Always use OCPP-based load balancing when possible.
That’s why Wattery requires that all approved devices support at least the Core and Smart Charging modules.
Want to dive deeper? Let’s keep going.
Vendor Lock-In and Cybersecurity
Cloud services are often marketed for their ease of use, and for good reason. But there’s another side to the story.
Imagine storing your important files, photos, and customer data in the cloud. Everything works great until:
The provider doubles the price
The service is shut down
A better and/or free alternative becomes available
You try to switch providers and realize you can’t. Your data is locked in, and you can’t access it elsewhere. This same risk applies to EV chargers and management systems if they rely on a manufacturer’s proprietary cloud service.
That’s why Wattery insists on the ability to connect directly using OCPP.
Some manufacturers offer Bluetooth-based apps to configure chargers, but if the company disappears, so does the app. Brands like Vestel, Garo, and Harju Elekter provide chargers that can be accessed without external apps. While this isn’t a strict requirement at Wattery, it’s highly preferred.
The problem becomes more serious in systems using master-slave, gateway, or edge device architectures where only one device connects to the internet and others depend on it. What happens when that one device is no longer supported?
Not all cloud services are bad. For example, Garo Connect makes life easier for both users and installers. Still, Wattery requires that you can access the charger directly if the cloud goes offline. We have nothing against clouds, only against cloud castles so tightly locked that you discover too late there’s no way out.
We know some customers have connected closed systems to Wattery’s platform because we technically can’t block any OCPP device. But we never highlight these in discussions. If asked, we always give a clear warning. We don’t want to be the ones dealing with the fallout when a customer finds out they were sold “openness” that turns out to be anything but.
We talk about switching operators every week with potential customers. This spring, even more so due to providers like Eways, Enersense, eChargie, and Etrel. Unfortunately, with closed systems, the outcome is often disappointing.
On Security:
From a networking perspective, EV chargers are “dirty” devices regardless of the brand. Wattery closely monitors which servers these devices connect to and for what reason.
With chargers that have built-in 4G, it’s not always possible to know exactly what data is being transmitted and where. There has been growing concern over backdoor access in energy devices like solar inverters and EV chargers.
There are three typical ways to secure your system:
The tinfoil model: Use Ethernet and allow only specific domains and ports
The basic model: Use a home router and connect the charger via WiFi or Ethernet
Custom SIM: Use your own mobile data plan from a carrier
Always ask the manufacturer what data the charger sends over 4G, even if it’s on a local network. 4G can also be implemented securely, as shown by Garo, Charge Amps, and Malmbergs, which offer manufacturer SIM cards that can be removed if needed. We don’t like eSIMs. They make it harder to manage access and go against Wattery’s values of openness and transparency.
If you want to dive even deeper into the world of OCPP, get in touch and let’s set up a meeting.
This is what we do at Wattery.
