SAE’s NACS certification is ready, and it’ll fix every EV charging problem at once

SAE has followed through on its plan to finish its NACS certification by the end of the year, and the NACS standard is now ready to go. And the new standard promises to solve a lot of charging problems in one fell swoop.

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, since Tesla is a majority of the US EV market, 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.

This led SAE, the professional engineering organization which develops industry standards, to take 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.

How NACS will solve several EV charging problems at once

We had another chat with Rodney McGee, Ph.D., of the University of Delaware, who chaired SAE’s NACS task force, and told us that the new standard will soon be announced by the White House. He was understandably excited about the standard getting finished so quickly, and told us how NACS is going to solve a lot of problems with EV charging all at the same time.

In particular, it should make charging installation cheaper for commercial entities, leading to cheaper and easier charging for businesses (including, potentially, for large apartment buildings); make charging more interoperable between commercial and personal vehicles; and unlock new possibilities for street charging for electric vehicles.

The main reason for this is the standard is preserving NACS’ support for 277 volts, as opposed to the 208-240 voltage of J1772. This simple change unlocks a cascade of benefits that should smooth out several charging problems.

Why does this matter? 277V is one phase of a three-phase 480V supply, which is the form that most commercial utility connections come in (particularly those that support DC chargers). Which means that secondary step-down transformers are no longer necessary for AC chargers, making EV charging installations cheaper and more efficient.

When you make EV charging installations cheaper and easier for businesses, this means more chargers at workplaces, giving people who can’t charge at home another option. It means more opportunity charging at any other place you might happen to park, and more opportunity charging means more EVs plugged in at any given time which means more battery capacity available on the grid in a potential V2G future.

Saving businesses money is all well and good, but the most important point here is that by making commercial installations cheaper, this means that mixed-use apartment buildings can more easily install banks of EV chargers, without needing big transformer rooms to further step down voltages. And that means that more people will be opened up to the convenience of having a charger at the place where their car spends the most time.

The news is even good for people who don’t have a parking spot – city-dwellers who use street parking. The NACS standard includes a provision that would enable the installation of chargers in lampposts, something that we’ve seen trials of in London. There have been similar efforts in the US, but those are subpar because the J1772 standard requires a permanently-attached cable, which means that streetside cables get dropped, broken, laid around, and otherwise abused.

The new NACS standard instead uses a standardized receptacle – which is in fact the same one used in the EU and China – which can be plugged into with a ~$100-200 carry-along cable that EV drivers can keep in their car (and the receptacle does have a locking mechanism). Making each driver responsible for their own cable makes maintenance easier in public spaces where otherwise, nobody’s really willing to take ownership of ensuring cables don’t get abused.

NACS also allows AC and DC through the same connector, unlike J1772. CCS is similar to the J1772 plug, but with an additional two pins on the bottom, so the connectors aren’t identical. With NACS, the connectors are identical for both types of charging.

Another potential upside here involves medium and heavy duty vehicles, which could charge at up to 52kW AC from the same receptacle as a light duty vehicle can charge at 20kW, by using 3 phases or 1 phase respectively. 20kW can be a bit on the low side for some larger vehicles – school buses and the like – so allowing those vehicles to charge at up to 52kW from the same place light duty can charge at 20kW would be a big boon as well.

And finally, all of these boons add together to a world where it’s easier to install and maintain chargers, and easier for everyone to be using those chargers wherever they’re parked, which means more cars plugged in at any given time. And if everyone is plugged in all the time, that means more capacity available for a potential vehicle-to-grid future. If V2G ever takes off, we will want to have as many cars plugged in as possible, because more cars plugged in means more capacity available for the grid. And that means making AC infrastructure cheap, which is what 277V support and carry-along cables enable.

There is one potential problem on the horizon, though: California and the US federal government (through NEVI) have both put a lot of money into charging station deployment, and the original intent of that money was to install roadside DC chargers that are as compatible as possible. So now, will those rules fully embrace NACS and allow the money to be used to install the new standard, or will they require CCS-compatible deployments so as not to leave an installed base of vehicles behind, even though CCS is now, effectively, a dead standard? (one compromise option being discussed is to require CCS for DC chargers, but throw full weight behind NACS for AC chargers)

This decision point is also a little ironic, since NACS’ existence seems to have been spurred on by NEVI in the first place. When the government offered billions of dollars to companies that install chargers with the restriction that those chargers be useable with multiple vehicles, that’s what got Tesla to finally offer a “standard.” At the time, it wasn’t really a standard because only Tesla was using it, and it was somewhat of a last-ditch effort to save the Tesla connector. Then, when Ford decided to use NACS, that’s what started all the others dominos falling. Now, NACS is dominant, but it only happened because of NEVI in the first place – and NEVI now has the difficult decision over whether to embrace the (positive) situation it caused, even if it will give some of the installed base an effective “use-by” date as a shift to NACS will inevitably mean fewer CCS/J1772 chargers over time.

City Dwellers’s Take

We’re actually pretty amazed that this standardization process finished already. SAE intended to finish by the end of the year, but standards can take a long time and require a lot of cooperation from organizations with differing motivations.

Part of why this process could be finished so quickly is because we’re now further into the world’s electrification journey, and auto manufacturers, many of whom now have departments getting into the charging business, can see the benefit of making charger installations cheaper.

And while we may have been a little hyperbolic in the title, this really does fix one of the few real problems with electric cars right now. There are a lot of perceived problems with EVs which rely on misconceptions, but one that isn’t a misconception is that there are bigger hurdles to owning an EV for people who don’t have a garage.

With cheaper AC charger installation benefits allowing better charging options for workplace, garage and street parking, this all adds up to a win for environmental justice. It makes EV charging easier for renters, or for people who otherwise do not have access to their own garage/off-street parking where they can install a charger. And that means more EVs in lower-income communities, and cleaner air too.

This has been a problem for a long time, and some piecemeal solutions have been proposed and are in the works, but this standard should help make that problem more solvable.

Ironically, the one thing the standard doesn’t solve is the problem we pointed out in the headline of our previous article on this – Plug & Charge. That article laid out how authentication issues are holding Plug & Charge back from being as good as it could be in the US, and unfortunately the SAE NACS standard (which it calls J3400) won’t solve that. However, work is ongoing on a solution for that problem, in a separate proceeding, and it seems like the NACS changeover may be the impetus needed to get it solved once and for all.