Tesla’s Charging System Is Going Wide, Finally Getting Certified

Jackson Wheeler
7 Min Read

  • SAE’s certification means engineering and development parameters have been established so developers can proceed with “many critical aspects of deployment and commercialization of the NACS connector.”
  • An SAE official said CCS chargers used by other automakers have “a bulky and hard-to-handle cable” and a problematic, damage-prone mechanical latch. (Pictured above is Tesla’s NACS charging connector next to the CCS alternative.)
  • Tesla wouldn’t have been eligible for certain federal funding unless its stations were open to vehicles using the widespread Combined Charging System (CCS) protocol.

On December 19, the global engineering organization SAE International (formerly the Society of Automotive Engineers) announced it had reached a milestone in setting standards for the use of Tesla charging, including the vaunted Supercharger Network, by the growing number of outside automakers that want to use it.

Tesla uses its own North American Charging Standard (NACS), which the company opened to other automakers in November last year. The Volkswagen Group is the latest to sign on, but beginning with Ford and General Motors it’s had a lot of company.

The standard is called J3400, and the milestone was the release of its Technical Information Report (TIR). SAE says the completion of the report “means certain critical engineering and development parameters have been established to allow developers to proceed with certainty about many critical aspects of deployment and commercialization of the NACS connector.” This is the first professional certification of NACS, complementing only some technical documents that Tesla has released.

Many non-Tesla automakers are currently using the Combined Charging System (CCS) protocol that was introduced by SAE’s J1772 standard in 1996. There’s also the so-called CHAdeMO standard, developed by Japanese automakers in 2010 and still popular there, but now on the wane in much of the world. The Nissan Leaf is a prominent user.

CHAdeMO was certified by another standards agency, the Institute of Electrical and Electronics Engineers (IEEE), after SAE decided not to take it on.

At stake is $7.5 billion in EV funds from the National Electric Vehicle Infrastructure program.

The certification process is “definitely not over,” Rodney McGee, who runs the Transportation Electrification Center at the University of Delaware and is chairman of the SAE J3400 NACS Task Force, told Autoweek.

“But a lot of the basics have been locked down—connection types, the way you plug in, the meat-and-potatoes items,” McGee said. “We felt it was important to get [the TIR] out this year because carmakers other than Tesla will be using NACS by 2025.”

McGee said CCS chargers have “a bulky and hard-to-handle cable” and a problematic mechanical latch that provided “opportunities for damage,” but he said CCS’ design is only one of the issues that has led to a high rate of non-operative CCS stations. He said the new standard contains upgrades that will make it cheaper to build charging infrastructure.

The technical report is a guide for “regulators, designers and engineers, people building stuff around NACS,” McGee said. It will be followed by “recommended practices” with safety requirements and other information, he said. “J3400 will gradually become more technically mature,” he said. The standard is expected to be released in the fall of 2024.

Sam Abuelsamid, principal analyst for transportation and mobility at Guidehouse Insights, told Autoweek, “It’s a good thing, especially since we’re going beyond just Tesla using the network. Having a formalized standard in terms of durability, dimensions, and other factors will hopefully ensure interoperability between all the automakers.”

Abuelsamid said the new standard will, among other things, preserve NACS’ use of grid electricity at 277 volts directly off the poles, without the need to step down to 240, thus enabling cheaper chargers and a 2% to 4% efficiency improvement. It means power poles could directly host charging plugs.

a tesla car seen charging at the tesla supercharger station

Bank of Tesla superchargers.

SOPA Images//Getty Images

Although on the surface Tesla’s opening its Supercharger network to other automakers appears to be giving away one of the company’s greatest advantages in the marketplace, there’s money involved. Specifically, the prize is some $7.5 billion in federal EV charging grants through the National Electric Vehicle Infrastructure (NEVI) program, set up to assist private companies in building stations.

But Tesla wouldn’t have been eligible for funding unless its stations were open to vehicles using the widespread Combined Charging System (CCS) protocol. Tesla, which lacks a publicity department, isn’t commenting on its motivations.

The Biden Administration’s Joint Office of Energy and Transportation said the release of the TIR moves the NACS standard “toward an open industry standard that can be updated and maintained through a collaborative industry process moving forward.”

Because many cars now being built or already on the road use the CCS connectors, charging stations are likely to maintain their availability at multi-wand public locations, though probably not indefinitely.

Automakers announcing their commitment to the Tesla system include—in addition to brands in the VW Group—General Motors, Ford, BMW, Honda, Hyundai, Kia, Jaguar, Lucid, Mercedes-Benz, Toyota, Nissan, Polestar, Volvo, and Rivian.

Stellantis remains a significant holdout, but it is partnered with GM and others in building a North American network with more than 30,000 charge points. Pending approvals, the first will open next summer.

Do you think the industry’s adoption of the Tesla charging standard will result in a more reliable and better experience for EV owners? Please comment below.

Headshot of Jim Motavalli

Jim Motavalli is an auto writer and author (nine books) who contributes to Autoweek and Barron’s Penta. He has written two books on electric cars, Forward Drive (2000) and High Voltage (2010), and hosts the Plugging In podcast.  

Motavalli’s writing has appeared in the New York Times, CBS Moneywatch, Car Talk at NPR, Forbes, US News and World Report, Sierra Magazine, Audubon, and many more. In his spare time, he reviews books and jazz.

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Jackson Wheeler is a skilled editor at Speedofdaily.com, specializing in automotive content. With a background in Journalism and Automotive Engineering, he combines his passion for cars with his writing expertise to deliver captivating articles. Jackson's deep knowledge of automotive technology and his racing experience make him a valuable asset to the team, providing readers with informative and engaging content.
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