An introduction to ISO 15118-20, the newest member of the communication standard.

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Did you know that the ISO 15118 communication standard currently consists of eight different parts? It can be overwhelming to work with this complex and future-proof technology due to the vast amount of charging-related use cases the standard covers. The good news is that ISO 15118 serves as a unified communication protocol that covers all charging-related use cases. However, this myriad of functionality also adds to its complexity. In this article, we won’t cover all the different parts that ISO 15118 comprises. Today, I’m going to take this opportunity to introduce to you ISO 15118-20, the newest member of the document family.

ISO 15118-2 Ed. 2 is now called ISO 15118-20

The International Organization for Standardisation (ISO) changed the part number of ISO/DIS 15118-2 (Ed. 2) to ISO/DIS 15118-20. The project team currently working on the second edition of ISO 15118 requested this change after the last conference call in December 2018.

This means that the former project title

ISO/DIS 15118-2 (Ed2): Road vehicles -- Vehicle to grid communication interface -- Part 2: Network and application protocol requirements

… is now called

ISO/DIS 15118-20: Road vehicles -- Vehicle to grid communication interface -- Part 20: 2nd generation network and application protocol requirements.

The “DIS” in the title is short for “Draft International Standard”, which is usually the first version of a standard that is available for purchase.

The main reason for this change is that ISO 15118-20 is not compatible with ISO 15118-2 because it comes with a series of changes and a whole new set of features. Among these changes are a rearranged message structure and newly added messages that account for features like wireless charging, bidirectional energy transfer, and ACD charging. ACD is short for automated connection device and refers to wired charging systems that don’t require the user to manually plug in a charging cable. The first ACD use case is mainly specified by Siemens and describes how buses can be charged via pantographs.

ISO 15118-20 also comes with a higher level of security since encrypting the communication channel between the EV and charging station using Transport Layer Security (TLS) is no longer just an option, but it is now mandatory for all use cases.

When will ISO 15118-20 be published?

Due to this change, the latest possible date to publish ISO 15118-20 as an international standard (IS) is now February 2021. However, the project team aims to have this part of the standard published by the end of 2020. The registered experts are currently gathering in weekly web conferences to discuss all open technical and editorial comments and to find solutions. By summer 2020, we should have a Final Draft International Standard (FDIS)  that reflects all of the final technical changes. Only editorial changes will be allowed once an FDIS has been published. In case you are not a member of the project team but would like early access to ISO 15118-20, you’ll be able to purchase that document through ISO.

Update Jan 18, 2020: The publication date has been updated, previously the blog post stated that ISO 15118-20 would be ready by Q1 2020 at the latest. The publication date has been shifted due to the enormous amount of work needed to consolidate all comments.

How will ISO 15118-2 evolve?

Introducing different generations of ISO 15118 as different document parts will allow for better revisions of each part. That said, what is the plan with ISO 15118-2? This first edition of ISO 15118 is currently being implemented and brought to market by EV and charging station manufacturers and service providers across the globe (see also my previous blog post on “EV Charging Communication Events and Trends In 2019”). But how can we handle necessary bug fixes with this protocol version?

One idea would be that CharIN, the Charging Interface Initiative e.V. behind the Combined Charging System (CCS), will provide amendments or a corrigendum for those parts of the document that are ambiguous and could cause interoperability issues between different vendors. It’s also possible that after having gathered enough input from the market, a dedicated project team could work on a second edition of ISO 15118-2 that could be published much more quickly than the three to four years that is usually needed for a new standard. It all depends on how fast the team members agree on the introduced changes.

Resources for your perfect jumpstart with ISO 15118-2

Are you already implementing ISO 15118-2 and facing technical challenges? Or do you want to dive into this technology but don’t know how to effectively get started? You’ve come to the right place. I’ve prepared a series of comprehensive resources for beginners and experts alike. Take a look at the ISO 15118 Manual and my online courses. If you’re interested in setting up a consulting session or if you have questions about the available resources, don’t hesitate to reach out to me directly via email. I look forward to hearing from you.

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