Nxu announced that its in-house developed megawatt charging solution, called NxuOne, nears field testing, as the company leaves CharIN association, which works on the competing Megawatt Charging System (MCS) standard.

Nxu - for those who are not familiar with the name - is an Arizona-based company that originated from Atlis Motor, which a few years ago intended to develop and manufacture an electric pickup truck. Today, Nxu is a publicly traded company (NASDAQ: NXU), engaged in battery cells (Qcell), battery packs (Qube), battery energy storage systems (Qube+) and megawatt charging solutions.

What we see in the top image is the company's NxuOne charging connector, which is expected to offer not only a very high power level of 1.5+ megawatts (MW) of direct current charging (and potentially up to a few megawatts in the future), but also alternating current (AC) charging - single-phase and more importantly three-phase. Please note four massive pins on the plug to support any charging scenario.

Nxu recognizes a necessity to support three-phase charging in many commercial vehicle applications and sees its chance to challenge the upcoming MCS charging connector (which is expected to go up to over 3 MW DC) because MCS does not support AC charging.

The Nxu's images also suggest that the NxuOne will be more compact (smaller and lighter) than the MCS:

NxuOne (right), Megawatt Charging Solution from Nxu

from left: Megawatt Charging System (MCS) and NxuOne, megawatt charging solution from Nxu

Three-Phase Charging

There is no discussion that the EV industry needs a proper DC megawatt charging solution, but some might wonder whether there is a need for three-phase AC charging in North America.

Well, apparently there is in many commercial vehicle applications. The base, single-phase SAE J1772 plug goes only up to 19.2 kW (80 A at 240 V) and the Combined Charging System (CCS1) DC extension does not support three-phase charging. In other words, there is a black area not covered by this pair of charging connectors.

The unfortunate lack of support for three-phase charging already caused a necessity to launch the SAE J3068 charging standard several years ago (in two configurations), which is based on the European IEC 62196 Type 2 (AC) and its CCS2 version for DC charging. The purpose of SAE J3068 was to charge medium- and heavy-duty electric vehicles in North America from three phases (as long as they have three-phase onboard chargers). There are many commercial three-phase installations available, up to 133 kW at 160 A and 480 V or up to 166 kW at 160 A and 600 V in Canada.

This is where we always return to the beginning and our starting point that only a charging connector that is universal enough to support all charging scenarios might be the ultimate one. The European IEC 62196 Type 2 with CCS2 version was a good (not perfect) candidate for that. It's easy, and near costless, to keep unused pins on a plug, compared to adding an additional plug standard just to handle some uncovered applications. Now, just imagine someone who is using SAE J3068 on its truck fleet, but without a CCS1 inlet, it can't use general charging infrastructure, at least not without an adapter.

Tesla's North American Charging Standard (NACS) does not support three phases as either, and this is probably its biggest flaw or mistake because with just a 10-25 percent size increase, we would have a potentially perfect plug not only for North America but for all global markets. This is the one time when maybe Elon Musk's team was not looking far enough (on the other hand, they had a lot on their mind when launching the Model S at the time). With a three-phase NACS, we could have just one plug for all light-duty electric vehicles on the planet.

New Battle? MCS, NxuOne or Tesla?

The NxuOne charging connector is an interesting concept, which on paper checks most if not all boxes - AC (up to three phases), DC at more than 1.5 MW (a few MW in the future, as we understand), and supporting high-voltage (beyond 1,000 V).

Of course, we are very cautious about it (the prototype unit even does not look as small as the concept one in the images), but it could be a candidate for heavy-duty vehicles and commercial applications.

Considering the ongoing transition from the CCS1 to the NACS charging connectors for electric cars, it seems that we have a second "battle" between the MCS and NxuOne. We guess that CharIN's position on MCS is too strong to be challenged by a start-up, but in the end, the largest EV groups will dictate their terms anyway.

"Reflecting recent developments in the EV charging industry, the Company also announced its intent to leave CharIN (Charging Interface Initiative e.V.), the international association that has been responsible for developing the Combined Charging System (CCS) and Megawatt Charging System (MCS) standards. Final publication of the MCS standard is not expected by CharIN until 2024."

One of the most interesting things will be Tesla's next move. The company so far uses some proprietary charging connectors on the Tesla Semi electric trucks. Below we can see the current charging inlet (left image) and the initial prototype (right image). Compatibility with the MCS in the future has not been confirmed.


Here is the Tesla Semi's charging plug (ready for 1+ MW charging using new V4 charging cable and stalls):


Tesla's initial prototype:


Nxu NACS Support

By the way, Nxu intends to support the NACS charging connector for light-duty vehicles as well, although noting "near-term" use, and believing that the NxuOne would be the long-term solution:

"The recent adoption of Tesla’s North American Charging Standard (NACS) by industry leaders Ford, GM, Rivian, and Volvo underscores the urgent need for reliable and high-powered charging solutions to meet growing demand across all market segments. Nxu endorses the market’s shift to NACS and confirms the Company will offer both NACS and NxuOne connectors at future charging stations."

Meanwhile, Munro Live's Sandy Munro and Cory Steuben recently had an opportunity to visit Nxu's headquarters in Arizona and show us glimpses of what Nxu is doing, including the NxuOne plug.

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