Electric Vehicles

Charging Plug Standards
Can we get our act together?

Mark D Larsen
October 28, 2011

Imagine this scenario: what if different makes of automobiles had incompatible fuel ports, so that gas stations used different sizes and shapes of nozzles on their pumps to accommodate only their preferred vehicle?

This is, in essence, one of the obstacles that has thwarted the widespread adoption of electric vehicles to date: different manufacturers of both EVs and their chargers have used incompatible plugs and receptacles.

This lack of cooperation and teamwork has always been a problem with our species. Think: VHS vs. Beta, Mac vs. Windows, QWERTY vs. DVORAK, DVD vs. Blueray, left- vs. right-hand drive, inches vs. centimeters, firewire vs. USB... the list goes on and on.

It is too soon to declare complete victory, but it does appear that "standards" for EV plugs and receptacles might emerge in the next few years. Below are the proposed alternatives.

The charging port in the Nissan Leaf has a CHAdeMO fast-charge
receptacle on the left and a J1772 receptacle on the right.

Here is the CHAdeMO fast-charge plug.

It is designed for use with 480V DC stations, capable of charging an EV’s battery pack to 80% in under 30 minutes. The Nissan Leaf and Mitsubishi “i” use these connections, even though the entire industry has not yet adopted them.

This is the J1772 plug.

It is used to charge at both 120V or 240V AC. It is now the standard plug-and-receptacle design which all automakers and EVSE manufacturers have adopted. (EVSE is an acronymn for Electric Vehicle Supply Equipment.)

It is worth noting that Yazaki continues to improve the exterior design of its CHAdeMO plug, as illustrated here.

And Sumitomo is also working on a newer, sleeker variation of CHAdeMO.

Although fast-charging was developed many years ago with CHAdeMO connectors, only recently has the Society of Automotive Engineers (SAE) balked at the design and decided that a different, “all-in-one” standard was necessary. This is the monstrosity that SAE is proposing, sarcastically referred to as the “FrankenPlug.”

German engineers are apparently trying to emulate the SAE effort by proposing this design for all of Europe. However, the top portion of the plug is not even compatible with the J1772 standard already established!

Instead, it appears to be a simplified variation on the German Mennekes design that the European Commission has inexplicably adopted as a “standard” for 240V charging rather than J1772.

Curiously, Tesla Motors has decided not to wait around for whatever “standard” finally emerges, and has designed its own unique plug and receptacle for the Model S.

The simplicity of Tesla's plug is admirable, but obviously Model S owners will have to also buy adaptors to use J1772, CHAdeMO, and/or SAE public charging.

As a matter of fact, Tesla is currently beta testing a CHAdeMO adaptor that Model S owners could buy someday... for $450! Evidently this adaptor will prove useful in Japan, where there are already nearly 2,000 such chargers. To date, I haven’t seen any indication that Tesla intends to also produce a FrankenPlug adaptor.

Now, to give you an idea of the vast array of incompatibilities that have been used up to this point, below are some plugs and connectors from years past.

Large and Small Inductive Paddles

Avcon Connector

Dodge EV Receptacle

Ford Focus EV “Mule” Receptacle

Ford Escape Receptacle 1

Ford Escape Receptacle 2

Aptera-2e Receptacle

Aptera-2e Plug

Saturn Hybrid Plug

Concept Chevy Volt Plug

Prototype Chevy Volt Plug

Prototype Chevy Volt Receptacle

Tesla Roadster Receptacle

Tesla Roadster Plug

Mini E Receptacle

Mini E Plug

Smart ED Receptacle

AC Propulsion eBox Receptacle

Th!nk City Receptacle

Project Better Place Nissan Rogue Receptacle

Original i-MiEV 120/240v Plug

Original i-MiEV 120V/240V Receptacle