100 Questions about Electric Vehicles

By David Herron

Why is electric vehicle charging not standardized, such that there is one common charging protocol?

Most car manufacturers now build electric cars, and with the improving price we might think electric cars are slated to take over, but a niggling little problem is still causing pain to electric car owners. There is not a common charging connector for DC fast charging that works in all electric cars, and instead there are three competing DC fast charging standards. Differing electric car charging connectors is a bigger issue than whether cell phones charge using Lightning cords or USB-C, if only because public charging stations cost $200,000 apiece.

We might wonder what the big deal is. In consumer electronics there is a dizzying array of different charging cords being used, and "we" successfully use these different charging cords. But those charging cord differences cause a problem. What if you've lost the charging cord for a given gizmo? A gizmo that can't be charged is useless. When every charging cord is different it's harder to replace a lost cord, and you end up with a brick unless you're lucky.

USB charging for consumer electronics introduced a breath of fresh air. Losing the cord that came with the device simply means getting another USB cord, which is a standardized part.

That's a circuitous way of saying why differing charging cords for different electric car models is a big deal.

Another example to consider is the parallel refueling infrastructure in liquid fuels (diesel/ethanol/gasoline) for cars/trucks/etc. The nozzle for each refueling nozzle is different. That's so one does not accidentally put in the wrong fuel, because the wrong fuel can damage the engine. Therefore at the refueling station we just pull up to the correct nozzle, and we're good to go.

With electric car DC fast charging the situation isn't quite as simple. Where most gasoline stations carry all three types of liquid fuel, electric car charging facilities only rarely carry all three types of DC charging equipment. It is common to find CHAdeMO and Combo Charging System stations colocated together, but rare to find those available along with Tesla Supercharger stations.

Just in case that terminology lost you, let's review the available methods for electric car charging:

  • J1772 for single-phase AC. There is a USA/Japan/Canada plug for this, and in Europe a different plug is used. Every electric car has one of these ports, using the same plug (per continent) meaning we can pull up to any J1772 charging station and be good. These stations are good for 6 kiloWatt charging or sometimes up to 10 kiloWatt.
  • CHAdeMO for DC Fast Charging from Nissan and Kia. It is the oldest standard for DC fast charging, and because of the Nissan Leaf success CHAdeMO stations are widely available.
  • Combo Charging System for DC Fast Charging from almost every other manufacturer (including Kia, who is switching to CCS). There are two different plugs used, one for USA/Japan/Canada/etc and the other for Europe, because of the different J1772 plug between those regions.
  • Tesla has a proprietary charging plug used for both single-phase AC and DC Fast Charging. It uses two variants of the plug, one for Europe the other for other countries.

Since diesel/gasoline/ethanol refueling exists in parallel, all these different refueling systems for electric vehicles could exist in parallel. While these electric car charging systems do exist in parallel, there are very few charging facilities where all are present in the same location operated by the same entity.

When Tesla installs a charging facility, it only contains equipment for the Supercharger network.

WHen ChargePoint or Blink or eVgo or Electrify America or others install a charging facility, it only includes equipment for CHAdeMO or Combo Charging System or both.

There are places where a Supercharger station coincidentally is located next to equipment for other charging networks. But that's an accident of fate rather than anybody's plan.

Charging system incompatibility is a pain point

The situation as it stands has pain. With consumer electronics, isn't it painful trying to find the correct charging cord for each gadget? Isn't it painful to lose the charging cord and be unable to recharge the gadget? With electric cars, what if you're driving on your last electron and arrive at a charging station only to find it is the wrong kind?

That's the situation with electric car charging. We could be driving a non-Tesla car, and arrive at a Tesla-specific charging station, and unable to charge. If you're lucky enough to have enough electrons to get to the next station great. Otherwise, even though your car is in front of a world class electric car charging station, you're stuck and unable to charge, and your only choice is a tow truck ride to a compatible charging station.

Many folks are not so savvy about current electric car charging practices, and they could become very frustrated. Do they know to install PlugShare (or equivalent) on their phone? Do they understand the different charging protocols?

It's widely known that a single charging standard is desirable, and that multiple charging standards causes pain to electric car drivers. Yet, we are in the situation we are in, and there are multiple incompatible charging systems.

Why is there currently multiple charging standards for electric vehicles?

Since there are multiple facets to the problem, we have to consider each in turn.

Europe versus North America/etc One of the differences is the physical plug format used in Europe versus other places. So far as I understand it, the European automakers were not beholden to use the SAE-J1772 physical plug format and therefore used a different plug. It's not too big a deal because the same J1772 protocol is used, and the migration of cars between Europe and North America is rare.

CHAdeMO versus Combo Charging System This issue is much more convoluted and has to do with the conduct of the SAE J1772 committee. The CHAdeMO fast charging standard was developed in Japan during the mid-2000's and was first deployed in 2007-8. This makes it the first DC fast charging system for electric cars. It was adopted by at least Mitsubishi, Nissan, and Kia.

When it came time for the other automakers to consider DC fast charging the problem came before the SAE J1772 committee. This committee is responsible for standardized electric car charging. The committee considered adopting CHAdeMO but rejected it for various reasons. CHAdeMO requires a second charging port, for example, and the J1772 committee desired integration with smart grid protocols that were not supported by CHAdeMO.

See EV DC Fast Charging standards – CHAdeMO, CCS, SAE Combo, Tesla Supercharger, etc

Therefore the Combo Charging System was defined by the SAE J1772 committee. Nissan has bravely stuck with CHAdeMO but it is the last automaker to continue with CHAdeMO. As of this writing in early 2019 the Combo Charging System is winning... except for ...

Tesla versus everyone else Tesla Motors sought to start selling the Tesla Model S in 2012, and designed in from the beginning a DC fast charging system. But Tesla used a completely proprietary charging port. The Tesla Supercharger system was unveiled in 2013, using the proprietary charging port, and running at a 90 kiloWatt charging rate when the competing DC fast charging ran at 50 kiloWatt charging.

What happened is Tesla needed to surpass the other automakers in every way possible. With DC fast charging, Tesla delivered 90 kW and then 120 kW charging several years before the other automakers graduated beyond 50 kW charging. That gave Tesla an advantage because Tesla Model S/X owners could take road trips of any length, where owners of other electric vehicles were hampered by fast charging that isn't fast enough.

But at the time frame Tesla chose to unveil the Supercharger -- there was no standardized DC fast charging available with those characteristics. Both CHAdeMO and CCS of that time period was limited to 50 kW. To have the advantage Tesla had to develop their own DC fast charging system.

Why is electric vehicle charging not standardized, such that there is one common charging protocol?