ISO 15118 info series   •   18. November 2017

A common question I receive from the EV community is whether there is a difference between ISO 15118 and DIN SPEC 70121. The answer tends to leave many of you quite surprised. This is an essential distinction to understand in order to make sure your products are interoperable.

The German technical specification DIN SPEC 70121 is based on an early, unpublished version of the ISO 15118 standard and defines digital communication between an electric vehicle and a DC charging station. DC stands for direct current, which means DIN SPEC 70121 covers only the DC charging mode whereas ISO 15118 covers both AC (alternating current) and DC charging modes.

The ISO 15118 series has evolved greatly since the first publication of DIN SPEC 70121 and this has lead to a host of technical differences between DIN SPEC 70121 and ISO 15118. DIN SPEC was first released in 2012 and updated in 2014, whereas the first version of the technical specification of ISO 15118 was released in 2014 and version 2 is on its way.

It’s like a dialect of the same language. If you don’t understand that dialect, then it doesn’t matter if it’s the same language or not: you can’t move forward with the conversation.

This means that a charging station that only supports ISO 15118 cannot charge an EV that only speaks DIN SPEC 70121. But if the EV is able to speak both dialects, then they can successfully enter a charging session – and vice versa. That’s where it becomes very important that you understand and apply this knowledge to your product line and future innovations.

Another key distinction between ISO 15118 and DIN SPEC 70121 is that the latter does not support Plug & Charge, meaning: no secured communication via Transport Layer Security (TLS), no digital certificates, and no XML-based digital signatures so authenticity and data integrity can’t be ensured.

DIN SPEC 70121 was created as an interim solution to get the market up and running until ISO 15118 was released. Unfortunately, it still prevails in various test installations at the ISO 15118 Testing Symposia (Video 1 of my free course “Revolutionize Electric Vehicle Charging” has visuals from the most recent symposia). But DIN SPEC’s days are numbered, as ISO 15118 and its wide range of additional features fast become the industry standard.

We’ll dive deeper about this important distinction in Advanced Course 1: Master the Communication for Charging Electric Vehicles of my upcoming teaching series. For now, please contact me if you have further questions or need additional clarification.

Tags of this article

  • DIN SPEC 70121
  • AC charging
  • DC charging
  • data integrity
  • ISO 15118
  • data security
  • Plug & Charge

Next article

Charging infrastructure   •   17. January 2018

The case for ISO 15118 and OCPP 2.0: preventative solutions to hacking charging infrastructure

RFID card technology is not working. Sure, it is the most widely used tool to charge electric vehicles but, at the same time, unsecure RFID cards put both vehicles and drivers at incredible risk to hackers. Electric vehicle charging stations haven’t yet been widely adopted ...

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Research projects   •   18. September 2017

Project Ultra-E realizes Public Key Infrastructures Needed For ISO 15118 Plug & Charge

We all know that the rise of e-mobility closely links to a charging infrastructure which is readily available, reliable, and sufficient regarding the number of charging stations installed. These are the primary concerns of those who asses for themselves if it is worth buying an ...

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