Tesla Announces The Opening Of Its Proprietary Charging Standard

Tesla announced on November 11 the opening of its proprietary charging standard, originally introduced in 2012 with the market launch of the Tesla Model S to handle AC normal charging and DC fast charging.

Since then, it was used by the company in North America and in some other global markets.

Tesla says that after more than a decade of use, and an equivalent of 20 billion miles (32 billion km) of charging, the proprietary connector is “the most proven in North America.”

Tesla decided to open the EV connector design to the world, naming it the North American Charging Standard (NACS), so any other company would be able to adopt it (instead of the CCS Combo 1/ SAE J1772 Combo or the already outgoing CHAdeMO).

“In pursuit of our mission to accelerate the world’s transition to sustainable energy, today we are opening our EV connector design to the world. We invite charging network operators and vehicle manufacturers to put the Tesla charging connector and charge port, now called the North American Charging Standard (NACS), on their equipment and vehicles.”

Tesla’s charging standard has been designed for AC charging (single phase) as well as DC fast charging, using “one slim package.”

The company officially revealed that the DC power output might reach up to 1 MW of power, which is two times more than in the case of the Combined Charging System (CCS).

Not only that, there are two configurations of the standard: for 500 V or 1,000 V, which are mechanically backward compatible. In other words, no change is needed to use the standard for the latest 800V or 900V battery systems.

“The North American Charging Standard exists in both a 500V rated configuration and a 1,000V rated configuration. The 1,000V version is mechanically backwards compatible (i.e. 500V inlets can mate with 1,000V connectors and 500V connectors can mate with 1,000V inlets).”

The maximum current rating has not been specified, although Tesla was able to successfully operate “above 900A continuously with a non-liquid cooled vehicle inlet.” That’s close to 1 MW.

“The North American Charging Standard shall specify no maximum current rating. The maximum current rating of the inlet or connector shall be determined by the manufacturer, provided that the temperature limits defined in section 8 are maintained.

Tesla has successfully operated the North American Charging Standard above 900A continuously with a non-liquid cooled vehicle inlet.”

Tesla notes that the connector has no moving parts, is half the size and two times more powerful than the CCS connectors. The difference can be seen below:

Tesla: North American Charging Standard vs CCS Combo 1

In the case of AC charging, the standard is single-phase and that’s probably its only drawback preventing it from global adoption, because in many markets (including Europe) higher power levels (11-22 kW) are available through three-phase circuits.

Tesla’s current basic specs for AC charging is 48 A at 240 V, which is about 11.5 kW (on par with Tesla’s onboard chargers). There is no real limit to the AC current level on the standard side because the limit is usually related to onboard charger or the infrastructure.

In the early days of the Tesla Model S/Model X, the company offered higher power levels of onboard chargers – up to 19.2 kW (80 A at 240 V), but even in North America, it was a bit high to accommodate. In Europe, such a high power level from a single phase on an individual household level is rather unheard of (instead, 22 kW is often available using three phases – 3x 32 A at 230 V, while 11 kW is easily available).

If only Tesla would develop a more universal 3-phase version (with unused two small AC pins in 1-phase markets) its standard would be a perfect solution, covering all applications around the world at the expense of a marginal increase in cost and space. The specifics of this one thing already caused Tesla to adopt the CCS Combo 2 standard in Europe and in most of the rest of the world.

The battle for Tesla’s North American Charging Standard (NACS) is now just for the North American market (and a small number of other markets).

Tesla points out that the NACS is the most common charging standard in North America:

• NACS vehicles outnumber CCS two-to-one
• Tesla’s Supercharging network has 60% more NACS posts than all the CCS-equipped networks combined

That difference is not expected to simply go away anytime soon, as Tesla has sold almost two out of three new all-electric cars in the US.

Tesla reveals that some charging networks already have plans to use NACS, which means DC fast chargers with Tesla-compatible plugs (without the necessity to use a CCS1 adapter, which Tesla also sells for $250).

EVgo already has some Tesla plugs at its stations for quite some time, but through the CHAdeMO adapter, which is limited to 50 kW. Read more about it here.

The question is whether other carmakers will be willing to ditch the CCS1 in North America and switch to Tesla’s standard.

Tesla invites competitors:

“Network operators already have plans in motion to incorporate NACS at their chargers, so Tesla owners can look forward to charging at other networks without adapters. Similarly, we look forward to future electric vehicles incorporating the NACS design and charging at Tesla’s North American Supercharging and Destination Charging networks.”

So far we saw only Aptera applauding the idea, although Aptera is a small company, which also does not need to redesign anything or provide backward compatibility to older vehicles. That’s an easy choice for them. Aptera previously suggested a nationwide Tesla charging standard.

While the Tesla’s charging standard is mostly associated with fast charging and Tesla Supercharging network, the switch from CCS1 (aka SAE J1772 Combo) to NACS, in the long term would also kill the SAE J1772 AC charging connector.

Why? Well, why would you install the J1772 on the vehicle side anymore if the NACS would handle both AC and DC charging, and an adapter for J1772 is a simple part (Tesla sells it for $50). Ford is even adding such adapters with the Ford F-150 Lightning (mostly for marketing reason).

It other words, the J1772 would gradually fade, just like the CCS1 and join CHAdeMO at the charging graveyard in North America.

The technical specification of the NACS can be found here, while for additional info, check the source links below.