Managing the Evolution of the EV Charging Standard

How and why SAE International’s standards experts are fast-tracking the adoption of the NACS charging connector for North America.

Startup EV developer Rivian announced in June, 2023 that it intended to adopt the NACS charging standard. (Rivian)

SAE International announced in late June, 2023, that it intended to standardize the Tesla-developed North American Charging Standard (NACS) EV charging connector for North America. SAE then created the J3400 NACS Task Force to expedite creation of the J3400 NACS Electric Vehicle Coupler standard.

Christian Thiele, Director, Global Ground Vehicle Standards, SAE International. (SAE)

Grayson Brulte, host of SAE’s Tomorrow Today podcast, subsequently interviewed Christian Thiele, Director, Global Ground Vehicle Standards, SAE International, and Dr. Rodney McGee, Ph.D., P.E. Chairman, SAE J3400 NACS Task Force and Chief Engineer at the University of Delaware, regarding the work of the J3400 Task Force and other aspects of standardization as electrification technology proliferates throughout the light- and heavy-duty vehicle sectors. This Q&A is an abbreviated portion of that full interview and podcast .

You’re going to standardize NACS. What does that process look like? How will you take what Tesla built with the NACS and standardize it for across the industry for use?

McGee: Typically, a lot of standards start off at the very conceptual stage where experts basically say, how do we want this to work? And so you literally start with a blank piece of paper and then you get some proposals and then, in, you basically coalesce on a single sort of solution. That process typically takes some time because you're creating something where there was nothing before – or there were things before, but they were different, had different requirements.

The NACS standardization process is a bit different: today that connector represents both a majority of use in full EV and also a [large] market share in charging stations, especially DC [fast]-charging stations. So what we're going be doing in the standards is really capturing the existing mechanical connector to make sure that when other manufacturers want to be interoperable with it, they have a standard to follow that will ensure that things work well.

The J3400 Standard covers only the connector, not other aspects of the charging process?

Thiele: The J3400 is just focused on the charger unit – the fixture itself. We have other standards that are working for the interoperability point of view, the communication point of view/ The standards back in the day were always focused just on the vehicle; the vehicle was a standalone entity. Now there are communication protocols that are happening with the vehicle, with the people, with infrastructure, with other places.

The standard for the NACS connector is going to go faster than your “traditional” standards process. How is that going to be achieved?

McGee: I think Tesla realized they needed to have a standard that was published by an organization – we use the term SDO, Standards Development Organization. They looked at the options in front of them. The two [SDOs] that would cover this kind of area are the IEC (International Electrotechnical Commission) and SAE.

Dr. Rodney McGee, Ph.D., P.E. Chairman, SAE J3400 NACS Task Force and Chief Engineer at the University of Delaware. (Univ. of Delaware)

Some of the international standards can take quite some time. This is due to the way that they, they're essentially through national committees. In SAE, the standards are developed by individual experts from a variety internationally from different suppliers, different automakers, general interests, and there's a much shorter process to take into account revisions.

The second thing is the fact that NACS is unique in that it already exists in large numbers in the real world. And we're not starting from a blank piece of paper. The SAE process can, when there is consensus on what we're doing – and in this case, there is, because it's already out there, especially when we talk about the mechanical coupler – move much quicker than would be typical.

What is that timeline for the standard? Has SAE or the committee made a public statement around a timeline?

Thiele: We're looking at publishing something inside of about six months and it'll be a technical information report. Ideally a standard usually is developed anywhere from 16 to 18 months as typical timeframe. We have been as quick as 10 to 11 months and this will fall around the 11-month window.