The Case for NACS over MCS

In North America, the positive synergies from Tesla deploying NACS exclusively for V4 and Semi Trucks far outweigh theoretical benefits from deploying MCS. Tesla is the only charge point operator with a cost effective path forward.

Cabason Supercharger with Truck Drive Through Spots
Cabazon Supercharger with eight truck drive through charging spots at the Morongo truck stop/travel center.
There are regular spots for traditional backing in of passenger vehicles that don’t tow.

What do we know, or believe

  • Update June 2023: Both Ford and GM have now partnered with Tesla and will switch over to NACS for their passenger vehicles. This is a massive development and basically deprecates CCS1. There is no longer critical mass for CCS in North America – if there ever was.
  • A fully loaded Semi with today’s batteries can go 500 miles on a charge. That’s 8 hours of driving at 62.5 mph. Mountains don’t have much influence, but cold, and speed, and weight do. Most trucks are not at the maximum weight all the time. This range will only get better as battery tech improves.
  • The Semi will use the new 1000V power train. “More vehicles coming with that”. We believe that the Cybertruck will use a 1000V power train. Possibly the roadster. Maybe other delivery vehicles.
  • Tesla developed a MW charger and will deploy it as V4 of their Supercharger starting in 2023. This will generate a nationwide network of 1MW chargers by the end of 2024.
  • NACS (“Tesla plug”) supports 1MW+ charging. When they announced NACS, there was no product that would require 1MW. Now there is. Almost certainly they will put this plug on at least some of the V4 chargers and some of the vehicles. NACS has been tested up to 900kW without cooling of the vehicle connector. Cooling that connector is no problem for a Semi. A Cybertruck may not need to cool the port, but if they have the parts, why not.
  • V4 will be used for Cybertruck, too.
  • Tesla loves to share components between cars. The Semi for example uses Plaid Motors, and Octovalves. This is leveraging all the learning from the other products, and full vertical integration on the software and hardware side.
  • Semi drivers must take a 30 minute break in the first 8 hours of driving. (California tried to enforce 30 minute breaks after 5h of work, but the trucker union sued successfully). There is an 11h driving limit per day. At 65mpg average, 11 hours get you 750 miles, and it takes 7.5 hours to drive 500 miles.
  • Tesla will have 50k+ Semis and 50k+ Cybertrucks on North American roads by the end of 2024. That will be a large majority of Semi trucks, and likely a majority of pickup trucks.
  • MCS is not final. The goal is to publish a final standard in 2024, two years from now. Tesla needs a plug for North America today.
  • Building a mega charger networks will be crazy expensive. Mega chargers are expensive as such, they will require large battery backup, especially in remote areas, and they will have minimal use.
  • Tesla is ramping up their Lathrop Megapack factory, and many, including Elon, believe that the Energy business could be bigger than the car business. Tesla may be able to sell Megapacks at insane margins, but can get them at cost for their own charging locations.
Graph of V2, V3, V4 ampacity and cross cut of V3 and V4 charging cables.
Graph of V2, V3, V4 ampacity and cross cut of V3 and V4 charging cables.

Deploying NACS across all V4 chargers and vehicles creates massive synergies.

  • Foremost, it solves the chicken-and-egg problem of deploying a charging network.
    Any existing, or future wide pull-through charging spot can be used by Semis as well as Cybertrucks (or other Teslas) towing. The big win here is that any deployed V4 can instantly be used by the existing fleet of 1M+ Teslas in North America. Installing twelve V4 supercharger at a truck stop in Minot, North Dakota will expand the Supercharger network for all Teslas. Once enough Semi start showing up in Minot, they can deploy more stations or add a downtown location for cars only. Tesla is already doing this e.g. in Cabazon, CA. Inyokern, CA is not as spacious, but a Semi could use the pull-through.
    Update June 2023: The NACS fleet just exploded, with Ford, GM, and soon other vendors switching to NACS.
  • Everything before and after the plug is shared between chargers and vehicles. Same V4 charger before the plug, and same 1000V powertrain after the plug. It makes no sense to artificially partition some of the chargers to only work with some of the vehicles. Cybertrucks could not use the Semi chargers, and vice versa. Some locations, like Minot, ND would need two stations, one of each.
  • Tesla could start deploying dual MCS/NACS charging stations. But that just increases complexity and cost, requires two cables, and doesn’t have benefits for Tesla, or Tesla drivers compared to a pure NACS approach.
  • Tesla could put dual NACS and MCS ports on the Cybertruck. But it’s not even clear those fit, and again, it increases complexity and cost for manufacturing, maintenance, and drivers. When the same outcome is possible with a pure NACS approach.
  • Even if Tesla deploys public chargers with MCS, they will have to be dual use with NACS to make financial sense. Only if they are available to the existing fleet of millions of Teslas, particularly those towing, and particularly Cybertrucks towing, will they start to generate revenue.
Cabazon Supercharger Aerial View
The Cabazon, CA Supercharger with 8 semi sized drive through supercharger stations.

Is 1MW enough?

One question is whether 1MW+ is enough for Semi charging. The semi can do that in almost all conditions. If the Semi can maintain a 1MW charge for 30 minutes it will add 250 miles to the range, for a total range of 750 miles, or 11 hours of driving at an average of 65mph, the max a single driver can legally do. 1MW charging is enough to cover practically all such situations. Even if on the occasional run a fully loaded Semi needs to stop for an extra 30 minutes, that is made up for by the benefit on all the other runs.

A Semi has about 12 Model Y worth of battery. Charging speed depends on battery size. All things equal, this requires a charging speed of 80kW for each twelfth. 80kW sustained is no problem for a Model Y. This is even before any improvements due to the new powertrain.

Tesla can likely sell a million trucks in the US to operators who will never run into any of these limitations caused by 1MW charging. It will take years to sell that many, and by then batteries are going to be improved, too.

There is another scenario, too. Tesla could deploy a different, proprietary plug with up to 2MW+ power as discussed by The Limiting Factor on YouTube. It negates some of the benefits of a shared plug, at the benefit of faster charging.

So what about MCS?

What are the benefits of MCS? The main one is that “it’s the standard!” It will have additional features, like higher rates (which are not critical), backward compatibility with CCS (useless for Tesla in North America), etc.

Contrast this with the problems. For one, the standard is not final until 2024. Tesla needs charge points today. The standard will be chunky and complex and likely more expensive to build and deploy than NACS.

But the biggest problem is that there is nobody waiting to build an MCS charging network. The capital cost of deploying a nation wide MCS network ahead of trucks is significant. EA and others are already struggling to deploy and maintain their CCS charging networks. There is nobody in the US who can build a mega charger network which will required not just chargers, but also significant infrastructure and in many cases local storage. The rest of the truck industry is hoping for Tesla to deploy a nationwide MCS network.

Tesla was in the same spot with CCS. CCS wasn’t ready (and chunky) when Tesla needed a plug. Tesla arguably should have opened up NACS before CCS. This time they did. NACS is out there for all to use (of course access to the network is not free, others are expected to contribute to the network build out)

If Tesla sticks to NACS in North America, then truck manufacturers have a hard choice to make: Contribute to Tesla’s infrastructure roll-out, and benefit from the whole network, or contribute to someone else’s rollout, and likely pay more, and get a much smaller network, or pray someone will build one for them, with plenty of tax dollars.

Update June 2023: CCS’ impending demise demonstrates that “somebody else will build it for us” isn’t working in the US. It didn’t work with CCS, and it won’t work with MCS. Any truck manufacturer will wait to see what Tesla does, and then will follow that. The risk of being left behind on the committee standard is not worth it. And Tesla has demonstrated they are committed to their charging network.

MCS is likely going the be the standard in Europe. Tesla is a member and contributor of CharIN. But Tesla won’t ship Semis and pick-up trucks in Europe until long after 2024. There are also more other providers in Europe that might deploy MCS charging points. And MCS will be compatible with CCS, which is on pretty much all Tesla’s in Europe already.

MCS makes sense in Europe. It makes no sense in North America.

Last Updated on June 8, 2023.