EV charging standards - the times they are a'changin

Discussion in 'General Science & Technology' started by billvon, Jun 9, 2023.

  1. billvon Valued Senior Member

    If you have electric vehicles, you need a way to charge them. And just a 120V outlet doesn't really cut it. So you need a connector that has to do a lot of things well - work outdoors, present zero shock hazard, be easy to use, carry hundreds of amps of current at up to 800 volts, and be able to 'authenticate' a car.

    If you go back to around 1990 there were half a dozen EV charging standards out there - odd outlets, paddle-like charging connectors, even an inductive charger that had no contacts at all. Nowadays there are four:

    J1772/SAE - this is both a level 2 and a level 3 standard (i.e. AC and DC charging.) The DC charger is VERY large and is basically two more terminals grafted on to the standard Level 2 charger. But the SAE endorses it which is a big deal. J1772 is also the standard for low rate charging.

    ChaDeMo - this is the Nissan standard. Also big and complicated, but cannot do level 2 also. This is level 3 only.

    Mennekes - this is the three-phase European standard.

    Tesla/NACS - this is the Tesla charger, which is level 2 and level 3 in the same form factor. Also the smallest/lightest.

    For a while ChaDeMo had the top spot purely due to the Nissan Leaf, which was the first EV. Then once the SAE standard came out it looked like that was going to be it. It worked well, except for being huge and hard to handle.

    But then Tesla released its charging spec as an open standard (North American Charging Standard) and started making noises about allowing other EVs to use their charging networks. Then a few weeks ago Ford announced it would offer some EVs with NACS charger ports, and Tesla said they would allow Fords to charge on their network. Yesterday GM announced they were doing the same.

    This is a pretty big change, because it means that Tesla now has:

    -the charging standard that everyone is moving towards
    -the smallest/lightest charging standard
    -the largest charging network in the world

    Tesla has been losing money on its fast chargers for quite some time; they saw it as a necessary step to selling a LOT of their EVs. And it worked - the model Y is now the best selling car in the world. But I am sure they, like everyone, likes to make money, and monetizing their existing network could do a lot for their cash flow, especially since the chargers are already there.

    (Obligatory statement: I have a bunch of patents on EV technology and I work at a company that repurposes old EV batteries, so I guess that I might somehow make more money if anyone reads this.)
    Yazata likes this.
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  3. DaveC426913 Valued Senior Member

    Yeah but what about your cryptocurrency interests?

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  5. Tiassa Let us not launch the boat ... Valued Senior Member

    Acutally, everything about the Tesla move sounds sinister, and mostly because it's Tesla.

    Something about it reminds me of the time Microsoft tried to own fonts, and the prospect of "allowing" other brands to charge on Tesla chargers is a whole new twist on the old software analogy about restricting the brand of gasoline a car might be able to use.

    Which reminds:

    Well, sure, but is any of that actually part of what Tesla does? That is to say, I actually don't quite care, but since you mentioned it, and given that Tesla's CEO is notoriously unreliable, the part of your post about how Tesla, "like everyone, likes to make money, and monetizing their existing network could do a lot for their cash flow", stands out.

    More than any actual conflict of interest, though, I would simply point out that the paragraph and its phrasing reads more like a political pitch for exactly the sort of machinations that make Elon Musk unreliable, and his commercial endeavors disreputable.

    As a business move, it makes perfect strategic sense, from the business perspective. For consumers, though, it's Tesla, and Elon Musk, and thus ought set off alarm bells: Here, we have our own standard, and will generously allow other brands to use it ... until we decide otherwise.

    Only a fool can't see the danger. (Remember, capitalists never do anything sheerly for the sake of human altruism; pretending otherwise, or simply ignoring that point, is precisely how we keep getting fooled again.)
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  7. billvon Valued Senior Member

    But that's the thing. They made it an open standard. Now anyone can build an NACS charger that is compatible with Teslas (and vice versa.)
    Not at all. But see below:
    See? There you go! My post must have been a political pitch for some nefarious reason, using Musk-ian machinations. And no one would have realized that without my disclosure of my work with EV's!

    But what is the political angle? Perhaps I want Tesla to succeed because once upon a time I had Tesla stock, and we occasionally repurpose Tesla batteries, and if NACS becomes the new standard I will benefit . . .. somehow. That must be it.

    Or no, that's too obvious. Several of my patents pertain to a completely different kind of charging method (now used by Witricity) and a completely universal standard would whittle away at them. So it's reverse psychology, trying to get people to actually oppose NACS! That's even better.
  8. billvon Valued Senior Member

    I just checked and my 401k mutual fund contains about 2% Fidelity Ethereum Index Fund which . . . is related to cryptocurrency! So my post above must have been promoting cryptocurrency somehow.
  9. Tiassa Let us not launch the boat ... Valued Senior Member

    In perpetuity? Do we have that explicitly? Like I said: Something about it reminds me of the time Microsoft tried to own fonts. TrueType became what it is because Microsoft failed. If we have it in perpetuity, then, whatever; the standard will be adjusted and refined over time according to need and science, and not private-interest priorities. The question of that open standard is whether that openness is revocable.

    To the one, there you go, that's the only question.

    To the other, we're Americans, Bill; you already know that question is more complicated than it needs to be.

    Not must; that's your own invention.
  10. foghorn Valued Senior Member

    We need to know, have you shares in Musk's Twitter too?

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  11. billvon Valued Senior Member

    Nope. But I do read tweets, so I am sure I am biased either for or against Twitter.
  12. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

    Interesting (?) article I came across recently on this very subject, likening it to the HD-DVD v BluRay debate, with NACS on one side and CCS on the other. With Ford and GM now siding with NACS, the future for CCS does not look promising.
  13. billvon Valued Senior Member


    CCS has a lot of baggage, because it started life as an AC adapter (the J1772 / IEC 62196-1 standard.) Specifically it was designed as an 80 amp connector with a very simple signaling scheme. When it came time to upgrade the standard, they couldn't repurpose the two AC pins for DC because 1) they couldn't take the current, 2) they weren't designed for 400VDC 3) the signaling standard didn't support it and 4) it had to be backwards compatible. 3) and 4) could be designed around - but 1) and 2) could not be.

    So the SAE added two huge pins beneath the J1772 connector and called it a "combo" connector. This made it much heavier, much bigger, much harder to insert - but with no real benefit since you were forcing those AC pins into their sockets for no reason on the DC charger version.

    Tesla's connector (the NACS) was designed to be small from the get-go. Only two high power pins, one medium power ground pin and two signal pins - so the connector was 1/4 the size of the CCS connector. It was 1/2 the size of even the AC-only J1772 connector. So it was much easier to use and easier for car manufacturers to find space for. It was also easier for charger manufacturers, since there is only one plug whether it's a DC or AC charger.

    There is no free lunch of course, and the additional penalty you get with the NACS standard is that the interface inside the car is much more complex. This is because the worst-case failure (the car accidentally connecting its 400V DC battery to the house 240VAC grid) is catastrophic, and will likely destroy both the car and the house. So you need a LOT of backup to ensure that does not happen. Specifically, Tesla uses two contactors (instead of one) to disconnect the battery, and the battery itself contains an internal pyro fuse that the car can blow if there is a risk of that connection happening. So all that means more cost, size and complexity.

    However, that complexity has now been shown to work, and manufacturers are starting to build cheaper contactors/systems to work with the standard. So the prices there are coming down.

    Now that Nissan has gone to the CCS standard, ChaDeMo is dead. And based on recent events it would seem clear that NACS is going to win.

    But wait! The feds have something to say about this. Due to an earlier agreement with the Society of Automotive Engineers (SAE) any new charging station that gets federal dollars has to have at least one CCS port. That's not the end of the world since you could easily do a 20-spot charger station with one CCS connector, but it will delay the phase-out of CCS.
    Yazata likes this.
  14. Yazata Valued Senior Member

    Good informative posts, Billvon. Thanks.

    I've heard talk (not sure if it's true) that the European Union has already dictated a single European standard (Mennekes?). Tesla suggested to them that Europe adopt the Tesla standard, but the EU replied that the decision has already been made and that's that. (Seemingly setting up a future US vs Europe VHS/Betamax format war.)

    Tesla already has the best charging network, at least in the United States. So opening it up to Ford and GM EVs will bring in a lot of new business.

    On the other hand, allowing other charger networks to serve Teslas might take away business...

    But it still might serve Tesla's purposes, since one of the reasons why people don't buy EVs is range-anxiety and fear of being stranded without a charge. Increasing the ubiquity of compatible chargers might help reduce that worry and improve car sales.
    Last edited: Jun 12, 2023
  15. billvon Valued Senior Member

    Yeah. That's a slightly more thorny problem since AC charging in Europe often requires three phases. So the connector has to be different for 3 phase charging.
    One estimate was an extra $2 billion in income a year.

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