ISO 15118 consists of seven parts. Each part covers a different aspect of digital communication between electric vehicles and charging stations. A hyphen or dash and a number denote the respective part. ISO 15118-1 refers to part one and so on.
Part 1 is called “General information and use-case definition” and is referred to as ISO 15118-1. ISO 15118-1 outlines the intention of the specification and explains the overall goals of the standard by defining terms and use cases.
Part 2 is called ISO 15118-2 and is entitled “Network and application protocol requirements”. I call ISO 15118-2 the core or the heart of the entire international standard because it defines the technical specifications of messages and their respective parameters. The messages this part defines are those that are exchanged between the EV and the charging station to realize the use cases defined in ISO 15118-1 and to establish a successful communication and charging session.
ISO 15118-3 is titled Part 3: “Physical and data link layer requirements” and defines lower-level communication (the data link layer and the physical layer). These layers establish the higher-level communication outlined in ISO 15118-2. This third part also concerns the interaction with another standard called IEC 61851 – which specifies analogue signals that encode the available amperage of a charging station.
Part four of this family of ISO documents relates to conformance tests for the requirements specified in ISO 15118-2. Part five refers to the conformance tests for requirements defined by ISO 15118-3. A conformance test is a set of rules that describes whether a certain input of data is valid with respect to both the data itself and the current state of the system that is being tested (EV or charging station).
ISO 15118-6 is called “Part 6: General information and use-case definition for wireless communication” and is one of the parts that does not exist as a standalone document anymore. While part six did make it to the official phase of Draft International Standard, the ISO and IEC joint working group decided to add use cases for both wired and wireless communication to the second edition of ISO 15118-1.
ISO 15118-7 is called “Part 7: Network and application protocol requirements for wireless communication.” This part was originally devised to add the technical requirements of wireless communication to the wired specifications outlined in part two. However, the joint working group decided to merge part two and part seven.
You can find requirements about both wired and wireless communication and charging in the second edition of ISO 15118-2.
This means that there are no documents behind ISO 15118-6 or -7, although both titles remain out of commission.
In contrast to parts six and seven, ISO 15118-8 remains as a separate document to specify the technical requirements for wireless charging communication on the lowest two communication layers. Part 8 is called “Physical layer and data link layer requirements for wireless communication”.
ISO 15118-9 is called “Physical and data link layer conformance test for wireless communication”. This specification is intended to provide conformance tests for part eight and completes the current list of required conformance tests for both wired and wireless communication.