Range Confidence: Charge Fast, Drive Far, with your Electric Car

By David Herron

A Field Guide to electric vehicle service equipment (EVSE's)

Being an identification guide to the electric vehicle charging equipment found in the field.

Ideally all electric vehicles are compatible with all charging stations. That way an electric car driver can arrive at any charging station and not worry whether they can use it. While this compatibility exists for AC Level 1 and AC Level 2 charging, it does not exist for other charging rates. See

Therefore we need to know how to identify the charging port (or ports) on our vehicle, and which charging stations can be used for what purpose.

An EVSE, or Electric Vehicle Service Equipment, is what we also call a Charging Station.

See also:

Typical AC Level 1 - line-cord charging station

These EVSE's are small enough to keep in the car full time. They plug into normal power outlets, and provide a minimal 1.5 kiloWatt (or so) charge rate. That's enough for about 4 miles of range per hour of charging.

The automakers mean for these to be a "last resort" charging solution, and that normally we'd use 6 kiloWatt Level 2 EVSE's. But many people are using these EVSE's as their primary charging station. An overnight 10+ hour charging session can give over 40 miles of range.

It's sometimes possible to modify these EVSE's to run at 240 volts, immediately doubling the charging rate, and possibly to run at higher power.

Out of the box the Level 1 EVSE's plug into normal household power outlets. In the US that means the NEMA 5-20 outlet shown here. When modified for 240 volts, the power cord is replaced with one that plugs into a 240 volt outlet. The modified charger can still run on 120 volts, and requires an adapter cord to do so.

Typical AC Level 2

Clipper Creek CS100 charging station

Level 2 charging stations are usually meant to be hard-wired to a junction box that's in turn hard-wired to a service panel. They're then physically mounted to a wall, or on a pedestal, or mounted on a concrete slab, and to be part of the physical infrastructure. Each manufacturer puts their own stylishness on the EVSE, which doesn't change the essential form factor - a box to hold electronics, a thick 25 foot cord, and a charging plug.

In this case, there's a holster for the charging plug, and a place to loop the cable. On the side of the pedestal is a 120 volt power outlet to support Level 1 charging.

J1772 charging port
"SAE J1772 7058855567" by Michael Hicks/Flickr "mulad". Licensed under CC BY 2.0 via Commons - https://commons.wikimedia.org/wiki/File:SAE_J1772_7058855567.jpg

These are the AC Level 2 (and AC Level 1) charging plug and socket pair that's used in North America.

The plug has connections for AC power and control signaling. The charging station and vehicle communicate about the allowable power level, so the on-board charger doesn't pop the EVSE's circuit breaker.

There are built-in safety features that may not be obvious just by looking at the connector. The connector pins have different lengths carefully arranged so that the EVSE shuts off the power before the plug is disconnected from the socket. When disconnected the J1772 plug does not have power.

European Type 2 charging connector

Mennekes type 2 charging plug and socket
Mennekes type 2 portable EVSE

While the physical connector is different, these work electrically the same as the J1772 plugs shown above. For better or for worse, the European standards group chose a different connector.

The line cord charger shown here supports single phase AC, at 240 volts, at up to 13 amps, and plugs into a standard Europlug outlet.

The Renault ZOE supports both AC Level 2 and AC Level 3 charging. On three phase AC, it can charge at 43 kiloWatts, using this same Mennekes type 2 connector.

CHAdeMO DC Fast Charging

CHAdeMO Plug – Source: http://en.wikipedia.org/wiki/File:CHAdeMO_Plug_VacavilleDavisStDC2.jpg
Source: Nissan

This is the CHAdeMO charging plug and socket. CHAdeMO was designed in Japan with its first deployment in 2008, making it the first DC fast charging system. According to the CHAdeMO Association website, over 10,000 CHAdeMO stations have been installed worldwide as of December 2015. Typical stations support DC Fast Charging at rates up 50 kiloWatts.

CHAdeMO's design does not integrate with the Level 2 charging socket. Therefore the car must support two charging ports, one for Level 2 in addition to the CHAdeMO port.

Because CHAdeMO was designed in Japan, it is primarily used by Japanese automakers. The best known CHAdeMO proponent is Nissan, whose Nissan Leaf sported a CHAdeMO port from the beginning.

While Kia is a Korean automaker, their Kia Soul EV has a CHAdeMO port. Kia has claimed the Soul EV can handle a 100 kiloWatt charging rate through its CHAdeMO port. [KiaChademo]

CHAdeMO's future is uncertain because the SAE designed a different fast charging protocol. A large contingent of automakers have announced support for CCS (see below), seeming to suggest the auto industry will ultimately settle on CCS for DC Fast Charging. But few of those companies sell cars with CCS ports.

Combo Charging System (CCS)

This is the Combo Charging System Combo 1 plug and socket (a.k.a. CCS Combo 1). It uses the same J1772 plug shown above, but adds two large pins at the bottom for high power DC.

The European variant, CCS Combo 2, takes the European Type 2 charging connector and adds a pair of high power DC pins.

Typical CCS stations run at 50 kiloWatts. In November 2015 some automakers announced they're developing CCS support for 150 kiloWatt charging rates. [CCShiPower] [AudiHiPower]

At the other end of the scale, BMW developed a 25 kiloWatt CCS-only charging station. The primary advantage is its low price and low installation cost. ChargePoint has adopted this station as one of its DC fast charging solutions. [BMWCP]

The dispute over which DC Fast Charging system will be dominant would theoretically complicate electric car ownership. One would arrive at a fast charging station uncertain whether their car was compatible. In order to resolve the problem, most charging station makers sell dual-protocol fast charging stations.

The user experience is similar to gasoline stations with multiple nozzles. Instead of selecting between Diesel or variants of Gasoline, you're selecting between CHAdeMO and CCS.

Among the reasons the J1772 committee developed CCS are

  • Single charging inlet to support slow and fast charging (versus two required for CHAdeMO)
  • Use smart grid protocols to control charging
  • Same connector serves multiple purposes

Tesla Motors Supercharger

This is Tesla's Supercharger system. Through one slim, light weight, easy-to-use connector, Tesla Motors supports single phase AC charging up to 20 kiloWatts, and DC Fast Charging up to 120 kiloWatts.

Seeing the dispute between CCS and CHAdeMO, Tesla Motors did not choose sides but instead developed their own fast charging system. Tesla CEO Elon Musk said they didn't like the styling or user experience of either system (both are ungainly).

However, there is a practical technical reason Tesla Motors could not just adopt CHAdeMO or CCS. Tesla's long range electric cars need a much higher charging rate than 50 kiloWatts. The Tesla Supercharger runs at 120 kiloWatts, or more, and the company wants to push the charge rate even higher.

Remember that a high charging rate (miles gained per hour of charging) is key to electric vehicle autonomy. To have the most autonomy, the charging rate needs to be as high as possible. Tesla's goal of encouraging rapid electric vehicle adoption meant pushing to much higher charging rates than other automakers.

Tesla Motors has three systems using their charging connector. This product is the Mobile Charging Connector, or Tesla's take on the line cord charger. Instead of a measly 1.5 kiloWatts, this baby supports any charging rate up to 10 kiloWatts and adapters are available for nearly any power outlet.

Tesla also sells a Wall Connector (shown above) that's installed at a fixed location. It can run at 10 kiloWatts or 20 kiloWatts, depending on options installed in the car.

The third system is the Supercharger network. Each Supercharger location has multiple stations, each of which runs at up to 120 kiloWatts charging rate. This is fast enough to provide a full recharge in about an hour, or about 300 miles of range per hour of charging.

Supercharger locations are being built along major highways and are primarily located at existing refueling locations. The network (December 2015) covers most of North America, large parts of Europe, and parts of China and Australia.

In Europe, Tesla has adopted this connector for charging. It supports all the charging modes described above - AC at 20 kiloWatts, and DC at 120 kiloWatts. Isn't it curious that Tesla can do DC Fast Charging through this connector, when the other automakers had to develop the much larger CCS Combo 2 connector?

Charging in China

Charging systems in China are still in flux with several ideas in development. This chart compares systems between China and elsewhere.

According to information from early 2014, China is using a charging connector very similar to the Mennekes type 2 used in Europe - not the connector shown here. But it only supports single phase AC charging up to 32 amps. That's good for 6 kiloWatts.

Historical charging systems

In the previous wave of electric cars - when GM's EV1 was king - two charging systems competed for dominance. Having two systems was painful, and we all supposedly learned to avoid that pain and stick to one charging system. Obviously that lesson got lost somewhere along the way.

"LA EV charging 08 2010 301" by Mariordo Mario Roberto Duran Ortiz - Own work. Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:LA_EV_charging_08_2010_301.JPG

On the left is an inductive charger made by MagneCharge. This was used on the GM EV1 and some other cars. On the right is a conductive charger, with a claw-shaped charging plug, made by AVCON.

The AVCON charging station formed the basis of the J1772 charging protocol. Using a suitable adapter, current electric cars can charge using an old AVCON station.

Range Confidence is Copyright © 2016-17 by David Herron

A Field Guide to electric vehicle service equipment (EVSE's)

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