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Standardisation in the EV industry has allowed not only better coverage in terms of charging compatibility but also helped ease a lot of the range anxiety and questions and scepticism of the naysayers of the EV industry.
When EV technology was first introduced, there wasn’t a fixed global standard for charging. Manufacturers used general hardware standards and proprietary backend systems that often made it difficult to use chargers for different setups.
Most manufacturers had the belief that by developing their own technology, they could secure more business, and their customers could enjoy the perks of exclusivity. For example, Tesla’s broad supercharger network was initially established to cater to Tesla customers only.
However, as the adoption of EV technology increased, so did the user demand for seamless integration across charging networks. This led to the adoption of standard protocols and ISO 15118, which highlight the requirement for charging networks to provide a “Plug and Charge” protocol that can enable multiple EV users to charge their vehicles.
Read on to find out more about the various EV protocols that enable cross-compatible use, how they work, and how they can be used to future-proof charging networks:
Open Charge Point Protocol, or OCPP, is an open-source communication standard. Meaning that anyone can access the protocol without special requirements or permissions. This protocol acts as a sort of universal language between EV chargers and the backend systems or the Charge Station Management Systems (CSMSs).
EV charging technology is based on a combination of hardware and software. Charging EVs isn’t as simple as just plugging in to a regular socket and connecting the charger to the car. There must be a “middleman” in between that allows for an optimal charging flow. This is achieved through software.
EV chargers use software to communicate with the charge station management system to determine the flow, wattage, and battery health of the EV to optimally charge the vehicle in a way that ensures the longevity of the battery. It accounts for various details like the ambient temperature, the type and capacity of the battery, etc.
This back-end software is tuned by vendors who may take liberties in establishing proprietary changes just for their hardware. However, this also limits the charger’s compatibility with other CSMSs.
This is where OCPP comes in. These open protocol chargers ensure that any charger can communicate with any management system, regardless of the vendor. This provides much-needed standardisation and enables EV users to expand their charging network options.
Through these open protocols, charging stations will not be locked into just one provider, which means that they can obtain superior flexibility, drive competition, and future-proof their business and EV infrastructure.
OCPP has had several versions since its inception in 2009. It was introduced for smart charging capabilities like load balancing and provided support for both SOAP and JSON messaging, both of which are software-related data management and communication web services.
Over the years, the protocols were updated to enhance security by adding encryption and transaction handling and by 2020, the protocols also adopted the ISO 15118 standards, which further enhanced compatibility.
The latest 2025 update to OCPP brings even more enhanced capabilities like Vehicle-to-Grid features, Distributed Energy Resource control, modular components, and renewable energy integration.
It is safe to say that these protocols will keep evolving with the demands of the customers, and we are very soon bound to see the day when EVs become fully compatible across regions and vendors.
EV charging stations have become very competitive over the years, and with the general public seeking more interoperability, it has become apparent that the future is based on open protocol chargers.
By opting to use OCPP, you will be able to avoid vendor lock-in and expand your station without worrying about compatibility issues. If you already have a pre-established charging network, then we recommend that you check the technical details of your management provider. If it isn’t competitive, then you can switch platforms without changing your hardware. This flexibility is crucial because it reduces long-term costs and secures your competitiveness over time.
Another fundamental protocol is the Open Charge Point Interface or OCPI protocol. This protocol allows for roaming and enables compatibility across EV brands. For example, using these protocols, a user with their dedicated user profile fixed to their car’s manufacturer can easily use their mobile application to access the charging network of other companies.
For instance, a Dutch EV driver travels to the UK. Instead of downloading a new app or signing up with a local charging network, they can simply use their existing Dutch charging application as they normally would.
Thanks to OCPI and roaming agreements, their app works on UK networks automatically, like ChargePlace Scotland or Shell Recharge, just as if they were charging back home. It’s seamless and allows for greater flexibility and convenience for EV users.
For the best results, and to allow EV roaming for users, we recommend exploring a combination of Open Charge Point Protocol (OCPP) and Open Charge Point Interface (OCPI). As mentioned above, this protocol standardises communication and data exchange, but it does so between the Charging Point Operators and e-Mobility Service Providers.
This integration enables EV owners to “roam” or use their singular home network account and mobile application to access stations on other networks. When used in conjunction with OCPP, users can benefit from cross-network authentication, authorisation, and even billing.
Through these open charger protocols, you can get several back-office capabilities that can allow you to have more control and flexibility to operate the charging station.
One of the biggest ways these protocols enable control is through real-time monitoring. By continuously monitoring the load around the premises, charging stations can effectively manage the load through Dynamic Load Balancing systems, which can allow for a more efficient charging experience.
These protocols also offer start/stop sessions and scheduled updates that can allow technicians to safely troubleshoot or maintain specific chargers around the charging station. Furthermore, the protocols also empower users to generate reports, handle billing, tariffs, and apply access controls.
Finally, through continuous firmware updates, the system can get better over time. Charging networks can also benefit from diagnostic reports and even analytical integration. With AI on the rise, we are bound to see an uptick in AI-powered analysis that can further help charging stations become more efficient and profitable.
Now that you know about the various open protocols for EV chargers, let’s take a deeper look at the layout of the charging station itself. Every charging station has a combination of EV chargers, and thanks to the adoption of open protocols, charging stations can reap the maximum benefit from a mix of chargers using back-office features.
The most common types of EV chargers, based on their charging speeds, are:
These chargers provide a power output of around 3.5kW and 7kW. Depending on the size of the EV’s battery, charging via a slow charger may take 4 to 8 hours. While they may not be ideal for people looking for a quick top-up, slow chargers are useful in places where the EVs are parked for a long time or overnight.
Fast chargers have an output of around 7kW to 22kW. These chargers can charge within 2 to 4 hours and are useful in locations where the EVs are parked for a couple of hours.
Rapid charging enables up to 43kW and 50kW of output. They can top up cars to 80% of the battery capacity within just 25 to 40 minutes. These chargers are in areas where cars are parked for a short while. It is important to note that these chargers require an effective load management system and the adoption of charging protocols to make them more efficient.
Rapid chargers are designed to provide a minimum of 50kW, with most charge points available at 100kW or 150kW. These chargers are useful in locations where the EVs need to be recharged in the least amount of time. Due to their immense load, they require the adoption of both OCPI and OCPP protocols along with an effective dynamic load management system for maximum effectiveness.
If you want to expand your EV charging network, then the best way to do it is to adopt these open protocols. The future of EVs is bright, and with more people shifting towards sustainability, it has become clear that the demand for EVs is here to stay and will likely increase over the years.
OCPP protocols are excellent for people looking to expand their internal charging network by seamlessly integrating a variety of load management systems. This can allow for future expansion without added costs and can enable you to smartly access your charging network and monitor its efficiency over time.
The OCPI protocol, on the other hand, is great if you want to open your charging network to a wide variety of customers. These protocols enable cross-charging interoperability and can allow different EV users to charge through your network through their mobile application.
The question of adoptability comes down to the size of your network, the number and types of chargers in your network, and your future expectations and expansion plans for the charging stations.
We recommend that you get professional technical help for a detailed electrical audit and for providing you with a future-proof and long-term strategy for your charging stations.
When it comes to installing EV charge points, you need to keep in mind the technical hurdles, procurement of hardware, integration of software, and the overall installation requirements to make the most out of your investment.
Even though OCPP and OCPI do not have installation mandates, the Public Charge Point Regulations 2023 highlight several back-end infrastructural best practices. Here are some of the important obligations:
Public chargers ≥ 8 kW (new) and ≥ 50 kW (existing) must accept contactless payments. This not only ensures standardisation but can also help charging stations remain competitive by addressing customer expectations.
When opting for OCPI, charger stations must enable consumers to pay via at least one third-party roaming provider. This ensures accessibility and helps the charging station remain interoperable.
For customer satisfaction and compliance, chargers must publish reference and availability data using OCPI in a machine-readable form. Any updates to the charger station, for example, in the context of availability, must reflect within 30 seconds.
Charging stations with a combination of standard and fast/ultra-rapid chargers must provide 99% uptime annually. This can be achieved through regular maintenance and by ensuring that all hardware and software components are designed as per the required standards.
Charging stations should provide a 24/7 free helpline and must clearly highlight the pence-per-kWh pricing around the premises of the station.
The installation process also comes with its set of technical requirements and must meet the electrical safety standards laid out in Part P of Building Regulations. They include things such as the exterior casing of the outlet not exceeding 0.2 cubic metres in size, the upstand (if any) being a maximum of 1.6 metres, and only one upstand allowed for each parking space.
In addition to that, the charge point must be installed close to where the EV will be parked, allowing the cable to reach it without being a tripping hazard. In the UK, the minimum recommended distance between the EV and the EV charger is 1.5 metres.
In reference to the length of the charging cable, it is usually 4 to 10 metres long, although the recommended length is 7.5 metres. When choosing the correct length for your charging cable, just make sure it is suitable and can reach from the EV charger to the EV with ease.
Some of the electrical safety standards that all EV charge point installations must follow include:
Choosing the right EV charger for your home or commercial property and navigating through all the requirements and regulations can be a bit tricky. For this reason, it is best to seek professional advice and have someone guide you along the way so that switching to EVs becomes even easier.
At Calder Electrical, we can install and maintain EV chargers for domestic and commercial premises in line with the current regulations and can offer a government incentive to reduce installation costs. We are authorised and registered OZEV installers, and our charge points come with a 3-year warranty.
If you own an EV or are planning to buy one, you will want to maximise recharge times and efficiency by installing an OZEV-approved charger in your home. Our team can visit you and survey your house to help determine your needs and requirements.
There are various EV chargers currently on the market, and it can be a little confusing to choose the best one for your home. We will take out the hassle and provide you with the most suitable and affordable option, ranging from the standard systems to the smart ones that are becoming increasingly popular.
Similarly, if you have a business that is looking to help employees or customers/clients charge their EVs at the workplace, you may contact us right away. We offer all kinds of different options to choose from, such as wall-mounted to freestanding pedestal units, and from fast charging to rapid charging units. Depending on the size and demand of the premises, our experts will help assess the best solution for your business’s needs.
We can also offer a PAYG (Pay-as-you-go) charging system and token-fed chargers with features focused on both the user and operator. This is something a lot of businesses are looking at currently as the market for EVs and chargers increases year after year.
Contact us here or call us at 0800 612 3001 for a quick consultation with our leading industry experts and more information on open protocols that future-proof your charging network.
Photo by Stephan Schwebe on Unsplash
