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SAE Develops NACS J3400 Standard In Record Time

Steve Hanley

Jan 1, 2024

Virtually every manufacturer who sells electric vehicles in the US decided to adopt the Tesla North American Charging Standard last year. But it’s one thing to say you are going to do something and quite another thing to actually do it. In the real world, standards must be agreed to and promulgated before much of anything happens. SAE International is the primary standards setting body when it comes to electrical devices, so the switch to NACS meant it had to move swiftly to get a new standard in place in time for companies to use it when they wanted to.

The Tesla NACS charging plug is a thing of beauty. In comparison, the CCS fast charging plug is big, heavy, and clunky. The NACS plug invites people to use it. The CCS plug dares people to use it. It’s a subtle point but an important one when you are trying to make people comfortable before trying something new.

NACS J3400 Standard Announced

SAE International has just released a Technical Information Report (TIR) for what is now called the SAE J3400 North American Charging Standard (NACS). In a press release, the organization said that in addition to benefiting EV drivers, the standard will help to ensure that any supplier or manufacturer will be able to use, manufacture, or deploy the J3400 connector for EVs and charging stations across North America.

The publication of the J3400 TIR comes just six months after SAE International announced it would standardize the Tesla-developed North America Charging Standard. The Joint Office of Energy and Transportation was instrumental in fostering the SAE-Tesla partnership to expedite plans to standardize NACS, which will play a key role in building an interoperable national charging network that works for most EV drivers.

“As the Joint Office supports the build out of a convenient and reliable national charging network, open and interoperable standards are crucial to ensuring that every EV can charge at any station,” said Gabe Klein, executive director of the Joint Office of Energy and Transportation. “We appreciate the commitment and knowledge of SAE and its experts from the automotive, EV charging, academic, and government sectors to make the charging experience easier and more accessible for Americans nationwide.”

“SAE J3400 provides a blueprint for cost effective mass electrification of transportation in North America,” added Rodney McGee, chairman of the SAE J3400 NACS Task Force and research engineer at the Transportation Electrification Center at the University of Delaware. “It facilitates broad interoperability for EV charging solutions by providing a unified, compact connector for both AC and DC charging. It is compatible with bring your own cord solutions that make J3400 an optimal approach for AC power transfer for street charging, parking garages/lots, and multi-unit or mixed-use buildings.”

This standardized approach also means that the same utility power feeds for DC fast charging can be utilized for single phase AC charging, which eliminates the need for separate circuit panels and additional step-down transformers at charging sites, which results in lower infrastructure costs and higher efficiencies.

“The J3400 task force represents government and industry collaboration at its best: working tirelessly to complete this milestone in reliability for EV drivers in six months,” said Christian Thiele, director, global ground vehicle standards, SAE International.

Standards bodies, which rely on broad based industry consensus, are sometimes criticized for moving slowly, but in this case, SAE has moved quite rapidly.  The SAE J3400 Task Force produced the Electric Vehicle Coupler Technical Information Report just six months after SAE’s announcement that it would standardize the Tesla-developed NACS technology.

Anyone who wishes may download the actual SAE J3400 Technical Information Report for a mere $195. We took up a collection while in the sauna at CleanTechnica global headquarters but because we were swathed in large towels with no pockets, we were unable to collect the required sum — or any sum of money at all, for that matter.

Switching To The NACS Charging Standard

Ford was the first manufacturer to announce it was adopting the Tesla NACS standard. By the end of 2023, it had been joined by Aptera, BMW, Fisker, General Motors, Honda, Hyundai Motor Group, Jaguar Land Rover, Lucid, Mercedes Benz, Nissan, Polestar, Rivian, Subaru, Toyota, Volvo Cars, and Volkswagen Group. By the time the year was out, only Mazda, Mitsubishi (which still uses the CHAdeMO charging standard) and Stellantis had yet to say they will adopt the NACS charging system. One wonders how long Stellantis will hold out.

Access to convenient fast charging is one of the primary factors cited by people who are reluctant to drive an electric car. The Tesla Supercharger network is the largest and most reliable fast charging network in North America. When more drivers stop worrying about where and how to charge, the EV revolution will pick up even more momentum.

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