In episode one, our engineers Hugo and Chad joined me to shed light on the key benefits of OCPP 2.0.1 over OCPP 1.6, specifically the new and powerful device management functionality, also known as “Device Model”.

Here’s the recording of our webinar from February 25, 2022. Towards the end, we also shared an example of how to visualise the device model using Sara, our modern and user-centred approach to a charging station management system (CSMS). You can find this at minute 35.52.

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Q&A around the OCPP 2.0.1 device model and ISO 15118-20

The last 15 minutes of the webinar were dedicated to questions. Below, we’ve linked the questions to the timestamps in the video and elaborated our answers in a bit more detail. Is there any other specific question you would like us to answer? Shoot me an email at marc@switch-ev.com.

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Q: Can you describe the AutoDiscovery process in the CSMS please?

A: The first time the charging station connects to a backend, it provides a base report and with it a full description of its logical and hardware components. An example for a logical component is the transaction controller (TxCtrl), which allows you to configure certain parameters that influence a charging session, like the start and stop point of a transaction. 

This means that once the charging station boots up and connects to the CSMS, the CPO gets a full picture of all the components the charging station entails. That information can be quite extensive, depending on the type of charger and what the charger manufacturer wants to expose through the device model. For efficiency, the message can be split up into multiple messages . 

The CSMS can then modify the configuration of these components, i.e. changing certain variables like the Heartbeat interval, power limits on a charger, and the security level (e.g. mandating the installation of certain digital certificates). Some of that configuration might be automated. 

Q: How to deal with legacy chargers in the network that are not compatible with all those new standards?

A: The update from OCPP 1.6 to OCPP 2.0.1 is likely to be more of a software than a hardware upgrade. If your charger is connected to a backend and allows firmware updates, there’s a good chance you can migrate your existing charger network to OCPP 2.0.1. Although there is some overlap between these two protocols, they are not backwards compatible. OCPP 2.0.1 entails a lot more use cases than 1.6 as it incorporates the learnings of the industry of the past years. This means that the codebase is bigger, requiring more memory space. 

Also, given the new security features in OCPP 2.0.1 (e.g. client side authentication and support for Plug & Charge), your existing charger needs enough memory space to store the relevant digital certificates. More often than not, charging stations that have been installed in the last decade have limited resources when it comes to CPU power and memory space, so this could become an issue. 

Furthermore, when it comes to ISO 15118, you also need to make sure that the charger is equipped with a HomePlug GreenPHY modem to enable the power line communication (PLC) required for an ISO 15118-based charging session with an EV.

We’re currently in a transitional phase where the vast majority of chargers are only equipped with OCPP 1.6 but the need for a more sophisticated charger management requires the adoption of OCPP 2.0.1. It is hard to predict when exactly the tipping point will be, but we’re confident that it will be within the coming year or two. The e-mobility market is still a very nascent one and studies have shown that more than 90 percent of the expected market (i.e. EV charger installation base) in 2030 is still ahead of us. 

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Q: Is there any update about ISO 15118-20? Also how different will it be from ISO 15118-2 regarding implementation and programming language used? 

A: Have a look at this article for more in-depth information on the new features coming with ISO 15118-20. It's a major milestone towards a universal charging standard that covers pretty much every possible use case for all kinds of EVs, be it cars, motorcycles, buses, ships, trucks, and even small aeroplanes. The new features include:

• Vehicle-to-grid (bidirectional energy flow) for both AC and DC, which is very likely the strongest reason to adopt ISO 15118-20 within the coming 2 years
• Pantograph charging for buses, aka ACD-P for Automated Connection Device for Pantograph
• Wireless charging
• A more explicit support for handling multiple contract certificates for Plug & Charge
• A new charging mode called Dynamic Mode, which puts the charger more in control of the charging process (better for ancillary grid services)
• Stronger data security, making TLS 1.3 mandatory for all use cases (with new, strong cipher suites)

ISO 15118-20 FDIS was published on February 18, 2022. You can purchase it online at Beuth publishing house (available in both German and English): https://www.beuth.de/en/draft-standard/iso-fdis-15118-20/350057248

The current status is a Final Draft International Standard (FDIS), which is basically a technical feature freeze. This means that only editorial changes are possible between the FDIS and IS (International Standard). So it's safe to start implementing based on this draft, there will be no more technical changes.

To clarify: ISO 15118-2 and -20 are not backward compatible but you can have both standards implemented on an EV or charging station. There is a mechanism defined in both -2 and -20 (SupportedAppProtocol) that enables the EV and charging station to agree on a mutually supported communication protocol.

Q: In the USA, most back end providers use OCPP 1.6 with no short term plans (< 2 years) to convert to OCPP 2.0.1. Comments?

A: We understand that due to the backwards compatibility issues and the significant increase in complexity, many CSMS providers and also charging station manufacturers are holding back on the adoption of OCPP 2.0.1. That’s exactly where we can help, both with Josev, our embedded operating system of CCS-based EV chargers, and Sara, our future-proofed  charging station management system. If you’re interested to learn more about Josev and Sara, then book your tour here. 

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Next episode: what’s new in ISO 15118-20?

Are you interested to learn more about the new ISO 15118-20 standard? Great, we’ve got news for you: our second episode “Switch to Clarity - What’s new in ISO 15118-20?” will take place on March 25, 2022.

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