SAE has voted unanimously to form a task force to expedite its NACS standardization process, and thinks that this process could finish by the end of the year – much earlier than we expected. We spoke with the chair of the task force for some insight on what the process might look like.

Tesla released specifications of its charging connector in November 2022. It called it the “North American Charging Standard,” which was somewhat of an absurd name at the time, given that Tesla was the only company using it.

However, Tesla’s argument was that most of the cars and most of the DC charging stations in America already used Tesla’s connector, so it should be considered a de facto standard anyway.

For a few months not many people took this seriously, until Ford shook up the industry by announcing it would adopt the NACS plug on upcoming vehicles. Soon after, GM made the same move, and now basically everyone else has.

So now that we have what looks like a standard, the professional engineering organization which develops industry standards has taken up the flag of creating a real, independent standard that is no longer in the hands of Tesla.

This is an important move because many governments and companies would understandably have an issue with a single company having control over a standard that, at this point, it seems like everyone is planning to use.

NACS standard could come this year, named “J3400”

We talked to Rodney McGee, Ph.D., of the University of Delaware, who is chairing SAE’s NACS task force.

The most important thing he told us is that the SAE Task Force aims to publish its work by the end of this year, only around six months after the start of the standards process. This is significantly faster than we thought it would take to complete the process.

McGee said that SAE is the only standards-setting organization that would be able to publish NACS this quickly, because the timelines for meetings and consensus in the ISO and IEC, two other standards organizations, are much longer due to the complex document processes used by these international organizations.

Another reason for this quicker timeline is because the NACS connector already exists on millions of vehicles, and makes up the majority of the installed base in the US. Since their stations are listed to UL standards and have been proven in the real world, many questions are already answered.

The standard will likely take the official name “J3400,” similar to the name of the current J1772 plug used in SAE CCS chargers. Though it could colloquially be known as J3400, NACS, or even “the Tesla plug,” depending on which name the EV-owning public seizes on.

But McGee told us that this his interest in NACS isn’t just on the DC side of charging, where most of the public’s imagination has focused, but on AC charging where the vast majority of actual charge sessions occur. It turns out that NACS is superior to J1772 for AC charging in one significant way – it can use an input voltage of up to 277 volts, whereas J1772 uses 208-240V.

This not only enables faster AC charging due to higher voltages, but more importantly makes for easier setup on commercial electricity supplies, which is often supplied as 480-volt three-phase power, of which a 277-volt single-phase circuit can be used for charging. This could make public AC charging – in parking garages for apartment buildings or workplaces, for example – cheaper and easier to install since commercial customers won’t need to install their own transformers.

McGee said that Tesla has been very helpful with the process in the last two weeks since SAE proposed making NACS a real standard, and is leaving the future of NACS up to a consensus-based standards process.

This has helped to allay some concerns across the industry, especially in Europe, which was skeptical that NACS could be a protectionist move. Europe has mandated non-proprietary charging connectors before and recently wasn’t happy about EV protectionism in the US Inflation Reduction Act, so this recent groundswell of support for a standard controlled by one American company was met with some skepticism. Having a standards-setting organization in control of the future of NACS makes it much more palatable (and might have led to Mercedes’ announcement to adopt it last week).

Why Plug & Charge is broken and how to fix it

Plug & Charge, a colloquial name for the ISO 15118 standard which allows simple “plug in & walk away” operation of public charging stations, has had a long and difficult implementation process. For years charging station providers have promised it’s just around the corner, but it seems to never materialize.

This is part of why Tesla leads in charging experience satisfaction, because plugging into a Supercharger is a simple process that takes seconds, whereas other chargers might require a subscription, a payment app, swiping a credit card, or at the very least waiting the better part of a minute for authentication to occur before charging initiates.

Besides these user experience issues, McGee pointed out one of the lesser-discussed reasons the standard has been hard to implement in the US, and how the SAE has been working on that problem since before NACS, and sees NACS as a opportunity to further its effort.

Plug & Charge requires a Public Key Infrastructure on the back-end to authenticate vehicles and payments. Public keys are a cryptographic mechanism that allow for secure authentication – one example is website certificates, so your computer can know that it is looking at a legitimate website.

In Europe, this PKI is provided by a company called Hubject, which verifies charging sessions on European public chargers.

But in the US, nobody has coalesced around a single company or organization to provide these certificate services yet. McGee said this is a major obstacle to Plug & Charge in the ISO 15118 standard, first published in 2014, since it is a technical standard did not initially prescribe solutions that were practical for the market.

SAE participants see the wider efforts around the NACS process as an opportunity to solve this problem going forward. Since the industry is shifting to NACS, this disruption could serve as the right time to solve this problem. It is engaging with industry (through SAE-ITC) to create a PKI for NACS which will hopefully solve this problem going forward.

Electrek’s Take

We were surprised to hear that NACS could be certified as a standard by the end of this year.

In the past, standards have taken much longer to develop – in fact, that’s why we even have the Tesla plug in the first place.

When Tesla was building the Model S, there wasn’t a standard that could do both AC and fast DC charging in the same plug. The rest of the industry – and the SAE – was slowly working out the CCS standard, but Tesla couldn’t wait any longer and went its own way, building the Tesla plug and later revealing the Supercharger network.

Now, more than a decade later, that Tesla connector looks likely to become the main charging standard in North America.

So the idea that this could be approved by the end of the year definitely raised our eyebrows, given the history of charging standards implementation and sometimes-long timelines involved.

And we’ve had a lot of questions about Plug & Charge and how long it has taken to implement in the past, so the conversation with McGee was enlightening on that front. It’s good to hear that a solution might finally be around the corner.

But this is a bit of a double-edged sword – while the NACS disruption gives an opportunity to solve the Plug & Charge problem for NACS, increased focus on the new charging standard might mean that nobody bothers to fix it for CCS, as it rapidly becomes considered a “legacy standard” the likes of CHAdeMO.