Is it true that the electric car companies can’t agree on a connector?

We need to have an electrician do some work at our house and I thought it might be fun to have an electric car charger installed. Of course, we don’t have an electric car, but maybe one day we will? We can’t fit a car into our garage (packed with junk due to brilliant architect’s 1960s decision to build this house with no basement) so the charger needs to be outdoors.

At first I was thinking “Shouldn’t this just be an outdoor 240V outlet?” Then I discovered that there are “charging stations” for sale. Is there anything more to them than an extension cord on a reel? It is the car that decides when to start and stop charging, right, not the charger?

Finally, even if we wanted to buy one of these cord reels, which one should we get? Some web pages imply that there has been a VHS v. Betamax situation. Is that all sorted out now by the Combined Charging System?

(Despite the fact that it is fun to ridicule the Tesla fan club, I think that if we did get an electric car it probably would be a Tesla due to the “dog mode”. See“Car/Kennel” for what I wrote about this in 2003.)

[Update based on comments below and further research: A hard-wired system seems to be required for reliability. J1772 is the standard connector except for Tesla, which requires a dongle adapter (i.e., there is no standard connector in the U.S., since the volume leader uses a different connector from everyone else). Total “Charlie-Foxtrot” as we say in aviation! Progress means that, unless you want to have huge amounts of power going through a dongle that is exposed to rain, every time you buy a new car you have to hire an electrician. If the family has two electric cars, it may need to have two different charging stations installed.]

Small parking lot in our suburb during lunch today included three levels of sanctimony: basic, plug-in, complete.


18 thoughts on “Is it true that the electric car companies can’t agree on a connector?

  1. Apple set a pretty high standard with one-off non-interoperable connectors. Everyone aspires to the success of Apple.

  2. The kind that you would install at your house is standard – it’s the J1772, which delivers AC at up to 6.6 kW, depending on the sort of circuit you have installed (you would nee 40Amps for 6.6) This can charge you up at a rate of about 25 mi/hour

    Where the standards war is going on is in the DC “fast charging” which you would never install at your house – it’s for large stations in parking lots that can deliver 50kW and up (Tesla can go up to 110kW now, they are going up. VW has demonstrated one that goes to 400kW. Of course, your car needs to support it.)

    There are 3 standards right now – the Japanese manufacturers have CHaDeMo, most of the American and Europeans have CCS, and Tesla has it’s own. I think CCS (which combines a regular J1772 port with DC fast charging, and thus does not need another port like CHaDeMo, will be the ultmate winner (Tesla is already adopting it for its European cars)

    • Why is there anything to “install”? Why wouldn’t it be a dryer outlet and then a cord with a J1772 connector on the end? A 30-amp 25′ dryer cord is about $100. Why is a “home car charger,” limited to a 25′ cord, different from a dryer cord? Because it can handle 40 amps instead of 30? Because it has a fancier connector on the end? Because it is mechanically tough enough to live outdoors?

    • Phil, one reason to put in a hard-wired charger instead of plugging it into a dryer outlet is they can charge at more amperage. I know tesla limits you to 40A (on a 50A breaker) when using a plug-in charger, but can charge at 72A using a wall connector with a hard-wired circuit.

  3. The filling of the garage with junk might be because of another reason than the lack of a basement. You need to hire a PhD in EE to install a 240V outlet near a car, preferrably someone who taught all of MIT’s CS courses & works as an expert witness. It requires a long, large cable from the meter.

  4. I have a charging station in my garage. But I live in Europe, so my situation may be slightly different because of differing electrical codes. I think it is a good idea to have the electrical installation ready to install an EV charging station, but I wouldn’t buy one until needed (prices are coming down all the time, and it is better to match it to the car). Get the thickest gauge wire you can, even if it’s overkill for the circuit breaker, the price difference will be peanuts compared to the cost of rewiring later. In our case, we got 10 mm2 gauge, which I guess is about AWG 7. Three phases plus neutral plus ground.

    I wouldn’t worry about the connector in the car, because you can always buy a cable with whatever ending you want. Yes, there are competing standards between European and Japanese manufacturers for the connector in the car, but it’s trivial to get a cable with the other ending. The two standards for normal charging are Type 1 (J1772, mostly on Japanese/Korean cars) and Type 2 (IEC 62196, or Mennekes, mostly in European cars). In Europe, the battle is over and Type 2 is the clear winner (often the only option in public charging places). Type 2 has the advantage of allowing CCS in a single connector in the car (although many cars don’t have it), which is used for quick charging (DC). There are two competing standards (plus the Tesla supercharger which is different) for quick charging: CHAdeMO (Japanese) and Type 2/CCS (European). Again, it doesn’t really matter because all quick charging stations provide both connectors, but the European connector is the de facto winner, and CHAdeMO is being phased out.

    It is true that the chargers are in the car, and charging stations can be seen as “just a plug”. But in reality it can be much more complex than that, and that’s why I don’t recommend buying one until you need it. Depending on the box and the electrical code, it may contain a residual-current circuit breaker type B, which protects against DC leaks (they are quite expensive, and mandatory in Norway for EV charging). It can also contain a transformer (from 115V to 240V to 400V, depending on the car and charging mode) and possibly a converter from three phases to one phase (don’t know if houses in North America typically have three phases). The question you should really ask is “how fast can the car charge?”. This varies a lot, mostly depending on the car, but also on your electricity supply and charging station. This page has a really useful table (in Norwegian, but simple to interpret) for different cars: . You see in the column “effekt” how fast cars can charge, and then which connector they have, how many phases they can charge with, maximum current, and quick charging connector.

    In the table above, you’ll notice that most cars on the market today charge only with a maximum of 3.3 kW or 6.6 kW. Even 6.6 kW happens quite rarely, because nearly all of those require 28 or 32A on a single phase. Electrical companies hate this, and often won’t allow such strong load on a single phase (it unbalances the other phases). Going from 16A (standard electrical installation in Europe) to 32A also requires some beefy rewiring. The ideal, and the future in Europe, is cars charging with 3 phases and 32A, giving about 22 kW power, but we’re still a long way from that (especially in Norway, where 400V between phases is rare). Some cars (Renault) only charge with 3 phases at 400V, and they can be noticed at public charging spots by the additional large transformer necessary to convert.

    • Forgot to say that there are charging stations with and without the cable (just the female plug). Ours is without, with a type 2 plug, so I can plug in a cable from any car.

  5. If you already have a 240V dryer outlet in your garage you can just buy yourself a “dryer buddy” and and skip the electrician.

    • That is a really bad idea. Adapting an existing installation that was never designed to operate for long periods at maximum load is a recipe for disaster. Plus, you’d be insane to charge with more than 6A from normal plugs — they have a tendency to overheat, melt, and catch fire when under continuous maximum load. The rules are getting stricter in Europe, and I guess in a few years it will be illegal to charge an EV from normal plugs.

  6. Jarle: You seem to know the most about this. It sounds as though one DOES want a hard-wired “charging station” (really just a cord?), not an outdoor NEMA 14-50 outlet. But I’m not sure why!

    But if one does hard-wire in a charging station, there are at least two standards: J1772 and IEC 62196-2 ( explains this a bit). If the house lasts 30 more years, how do we know that the U.S. won’t decide to abandon its J1772 standard in favor of this European -2 standard?

    • The two main reasons to have a charging station vs. a NEMA (or Schuko) plug are safety and convenience. While NEMA 14-50 plugs can handle high loads, they were not designed for continuous maximum load for long periods (they were designed for driers or ovens that are not always on). Regular EV charging in this way is considered a fire hazard. Also, charging stations typically either have one or are in a circuit protected by a RCD type B, which is becoming mandatory in many countries for EV charging. This RCD type B (and other electronics) is why NEMA/Schuko EV cables often come with a large brick between the wall plug and the connector the car. So if you have a charging station, you can just have a type 2 to type 2 or type 1 to type 2 cable, which don’t have the brick.

      I don’t know what type of charging stations you have in the US, but I strongly recommend getting one without a cable because then you get into the problem of the two competing standards. The standards are electrically compatible, so you can have cables with either end connector (e.g. type 1 in the car to type 2 in the wall plug) and a charging station with a female plug is the most future-proof option. For example this one: (costs about $500 in Europe). Another advantage of this type of charging stations is that they let you adjust the maximum charging current, so you don’t always have to charge at maximum load.

  7. Most US Tesla owners charge from NEMA 14-50, this is most universal option that will work for any electric car and charge at almost maximum rate available. (Some older Teslas had 72A charger, but current charger is maxed out at 48A).

    Tesla comes with NEMA 14-50 plug. If you have any other high-amp outlet in garage, Tesla sells all kinds of possible plugs. You might need matching extension cord, available at Amazon – Tesla’s cord is 20 feet. (I used extension cord and NEMA 6-20 plug for months before installing Wall Connector)

    “Not designed for continuous use” is nonsense since all electric codes expect potential continuous use.

    • ““Not designed for continuous use” is nonsense since all electric codes expect potential continuous use.”

      By continuous I meant several hours (e.g. overnight). Again, I don’t know the codes in North America, but I assure you that in Europe normal plugs are not designed for continuous use at maximum load. A typical Schuko plug is rated for 16A at 230V, but any use above 10A is risky. I have personally seen plugs overheating and melting from charging electric cars at 16A from a Schuko plug (which is still technically legal, but will probably soon be outlawed). For that sort of application, you have IEC 60309 connectors, which are used industrially for applications with heavy loads (in fact, in Europe the cheapest way to connect an EV charging station is to get an electrician to connect an IEC 60309 plug, and then the owner can legally connect any charging station to that plug).

    • Jarle, I agree that there could be problems with installation not up to the code and cutting corners, cheap parts, etc. especially in the 60ies house. NEMA 14-50 is for high-power applications, like dryer, which can easily run all day if there is a lot to wash. Tesla always caps charging to 80% of max for connection used. I.e. it draws 40 amps in this situation, of course there could be problems with some particular installation, but for most users it’s completely OK. Also, if there is a concern, you can configure tesla to draw less amps.

  8. My favorite part of this post is that a 60’s architect is responsible for making you 1) buy or rent a house of inadequate square footage, and 2) filling your garage with junk.

  9. The recommendation for buying quality 14-50 receptacles is totally valid. Hubbell is one manufacturer of quality receptacles of this type. In the US, devices should not be operated continuously at greater than 80% of the rating, which would be 40 amps. The 14-50 can be used at 125V, but typically is wired to provide 240V. Jarle, in a comment above, says most EVs don’t charge above 6.6 kW. This would be 27.5 amps at 240V, well within the 40 amp continuous load window. Obviously, 6.6 kW would be 52 amps at 125V, so anyone charging at 125V better be careful (limit charge rate to 5.0kW/40 amps). In general, NEMA power plugs and receptacles used at these voltages and currents should not be unplugged/plugged a bunch (daily) of times. The connector at the vehicle end of the cord is (hopefully) a design more suitable for this type of use. I would like to get in a plug for Tesla ….

Comments are closed.