History
Tesla developed a proprietary charging connector for the Model S in 2012 and used it on all subsequent vehicles, including the Model X, Model 3, Model Y, and Cybertruck. As part of its business strategy, the company also built the Tesla Supercharger network across the United States.[6]
Following the passage of the Infrastructure Investment and Jobs Act (also known as the Bipartisan Infrastructure Law) in 2021, the U.S. government announced $7.5billion in subsidies to support the development of a nationwide network of fast chargers at least every 50 mi along America's highways. To qualify for funding, chargers were required to be accessible to multiple brands of electric vehicles.[7]
In response, in November 2022, Tesla introduced the North American Charging Standard (NACS), an open standard based on the physical design of its earlier proprietary connector.[8][9] However, unlike the original Tesla connector, which used CAN bus communication, NACS employs the ISO 15118 protocol used by CCS1, allowing for vehicles with a CCS1 port to charge at a NACS station using an adapter, and allowing Tesla vehicles to charge at a CCS1 station using an adapter.[10] Tesla vehicles built before 2021 require an ECU retrofit to support charging at a CCS1 station. The Supercharger network remains backward compatible with both the original connector and NACS.
Tesla promoted NACS as offering several advantages, including a more compact design, a Tesla vehicle fleet that outnumbered CCS1-equipped vehicles by a margin of two to one, and a Supercharger network with 60 percent more stalls than all CCS1-equipped networks combined.[11][12][13][14] Commentators described the move as a last-ditch effort to save the Tesla connector as federal funding under the Infrastructure Investment and Jobs Act supported the expansion of CCS1 infrastructure.[7]
In May 2023, Ford Motor Company became the first major automaker to announce plans to adopt NACS. Ford stated that beginning in 2025, all new electric vehicles would feature native NACS ports, with earlier models able to use NACS chargers through an adapter starting in 2024.[15] Ford's announcement began a rapid shift in the industry, with other manufacturers making similar announcements throughout 2023 and early 2024, leading to widespread industry adoption.[7]
Observers noted that the broad shift reflected recognition of the Tesla Supercharger network as among the most reliable and extensive, and that NACS offered advantages in design and usability. Analysts also suggested that charging infrastructure could become a recurring revenue source for Tesla.[16]
On June 27, 2023, SAE International announced plans to standardize the NACS connector as SAE J3400.[17] In August 2023, Tesla licensed the design to Volex to manufacture NACS components.[18] SAE published the "technical information report" on December 18, 2023,[19] and the "recommended practice", with "NACS" redefined as the "North American Charging System," on September 30, 2024.[1]
Following widespread industry adoption, the U.S. government publicly endorsed NACS in December 2023. The Federal Highway Administration announced plans to integrate the SAE-standard NACS plug into eligibility criteria for federal charging infrastructure funding.[20]
Tesla officially opened more than 15,000 Supercharger stalls to Ford owners on February 29, 2024. The company reported that technicians had retrofitted many stalls with updated electronics to support both CAN bus and ISO 15118 protocols, enabling compatibility with CCS1-equipped vehicles. Tesla indicated that retrofitting work would continue across its network.[21]
