EV Charging Standards: Transitioning towards Tesla’s NACS

September 7, 2023

EV Charging Standards: Tesla’s NACS vs. CCS

With the increasing global adoption of electric vehicles, the question of EV charging infrastructure takes center stage.

Do we have enough charging stations, are they reliable, and how can we establish a dense and dependable network worldwide?

The issue becomes more complex when we delve into the types of electric vehicle charging. Apart from distinguishing between slow AC and fast DC charging, various charging standards have evolved over the years. Because different automakers use different connectors, and depending on your location and the type of electric vehicle you drive, you may end up using different charging stations.

But what if we had a global charging standard so that everyone could plug in anywhere? This is far from reality…


EV Charging Standards in the US

In the US, there are currently three main types of charging connectors.

  • CCS Type 1 (CCS stands for Combined Charging System as it combines AC and DC charging), which is basically used by almost all other automakers except Tesla.
  • Tesla’s connector, which is increasingly referred to as NACS, the National American Charging Standard,
  • and CHAdeMO (mainly for the Nissan Leaf).


Transitioning from CCS to NACS

In the past few months, established automakers like GM and Ford, who are currently working with the CCS standard and collaborating with third-party charging network providers, as well as startups like Rivian, who are investing in their own charging infrastructure network using CCS Type 1, have announced that they will be transitioning to the Tesla connector. This means, their future electric cars will be shipped with a NACS charging port.

This raises many questions. Why should we switch to NACS when CCS Type 2 is mandated in Europe? Is NACS better than CCS Type 1 in the USA? Will this transition resolve non-Tesla EV driver’s issues with CCS type charging offered by third-party providers?

Tune in to the interview with electrification expert Matt Hortop, where we discuss the following topics:

  • What is a charging standard and who defines it?
  • Why are there so many different charging standards in the US and only one major standard in Europe?
  • Will we ever have a global charging standard?
  • Why are American automakers transitioning over to Tesla’s connector?
  • Is the Tesla connector better than CCS?
  • Will a change of connectors change the reliability of existing third party charging providers?
  • SAE’s activities in the EV charging sector


Matt has worked in the EV battery and fuel cell industry since the 90s for legacy automakers such as General Motors, Opel, and Volkswagen. He was also the technical director of the electric powertrain at Rivian and today he works at AVL as technical specialist for all things electrification. He is sharing his expertise and thoughts around EV charging, as he is also the chair of the SAE and SAE ISO committee in the area of electric vehicle charging.


My Take Away for EV Charging Standards

In general, it’s a really good thing that we want to establish one unified charging standard here in the US. If we look at Europe, the CCS Type 2 charging standard was mandated from the beginning, so even Tesla and Nissan adapted and also offers CCS Type 2 in Europe. There’s only one standard, which is not only very convenient for EV drivers but also for the entire business model, as every charging network provider offers only one charging connector.

Now, here in the US, it probably would have been best to have CCS Type 2 too to align with Europe, but for some reason, everyone is switching to the Tesla connector.

I believe this transition to NACS is due to the fact that Tesla offers an extremely reliable charging experience in the US. It’s seamless and just works, whereas third-party charging stations offering CCS Type 1 have trouble achieving the same level of reliability.

The problem I see is that people are attributing the issues they experience with these third-party network providers solely to the connector type, and as we have learned from Matt, this is not the case – it is not the connector’s fault!

The charging reliability issues we experience with some third party charging network providers seem to stem from the fact that the charging network provider is a different entity than the electric vehicle maker, so the products don’t seamlessly integrate – there are communication issues, and troubleshooting responsibilities are not handled correctly.

So, the connector and the standard we are following are really just the design, in simplified terms, “the plastic you hold in your hand” when you plug in. Arguably, the Tesla connector has a nicer and maybe more user-friendly design compared to CCS1.

Now what does this transition mean for EV drivers. Electrify America and all other charging network providers will probably offer adapters for a while and then simply switch the connector. They will do it because they want the business. It looks like there will be a transition period for a few years where we will have dual handles and work with adapters, but CCS 1 will gradually phase out, and we will have Tesla’s National American Charging Standard everywhere. But, again, changing the connector does not mean your charging experience will be better!

Overall, in my opinion, this whole movement seems to be a bit rushed. I wish legacy automakers would have invested in independent research on today’s charging issues and presented comprehensive arguments for transitioning to Tesla’s national charging standard in the US when this is clearly a different trend from what happened in Europe.