Society of Automotive Engineers announces electric car charging plug standard


October 18, 2012

The SAE J1772 combo plug and receptor

The SAE J1772 combo plug and receptor

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The electric and plug-in hybrid car industry is learning the lesson of the mobile phone makers. Instead of allowing a plethora of incompatible charging plugs to sprout up, the Society of Automotive Engineers (SAE) International hopes to forestall confusion by settling on one charging plug design for North America. SAE has selected the J1772 combo plug as the standard, which uses paired couplers to allow for both AC and DC charging using the same plug.

Published this week, the SAE International decision marks the first official charging standard for North American cars. According to SAE, it was the result of consultation with 190 “global experts” from the automotive, charging equipment, utilities industries and national laboratories.

The J1772 has two charging plugs incorporated into a single design and is said to reduce charging times from as long as eight hours to as little as 20 minutes. It’s based on the 2009 J1772, which had only an AC charging plug. The current version includes a DC plug underneath the AC plug, which means that not only are both options available, but cars with the older J1772 couplings, such as the 2012 Nissan Leaf and 2013 Chevrolet Volt, can still use the new plug.

The dual capability is because AC and DC each have their strengths and weaknesses. AC is easier to access, since it’s mains current and the car's on-board system can rectify it into DC to charge the battery. The problem is that beyond a certain point AC has heating problems for the car, so charging is inherently slow. DC is much faster – theoretically limitless, but it requires an external charging station. The choice of currents means that car makers don’t need to choose between plentiful but slow, and fast but scarce.

The J1772 combo plug pushed out its rival, the pictured CHAdeMO plug (Photo: C-CarTom)

The new standard also sets charging levels and safety features for the plug – those features include its ability to be safely used in all weather conditions, and the fact that its connections are never live unless commanded by the car during charging.

J1772 beat out its main rival, the Japanese CHAdeMO plug (which is also available as an option for the Nissan Leaf and is used in over a thousand chargers installed in Japan), along with Tesla’s proprietary Supercharger system. Whether the SAE standard will see an end to these rival plugs or the beginning of an automotive version of VHS versus Betamax remains to be seen.

Source: SAE International

About the Author
David Szondy David Szondy is a freelance writer based in Monroe, Washington. An award-winning playwright, he has contributed to Charged and iQ magazine and is the author of the website Tales of Future Past. All articles by David Szondy

Sadly a standard 50 amp 120-240vac range or dryer plug would have done fine at far lower cost instead of this unit which costs 10x's as much.

Maybe it can be split so home chargers only get the part it needs and not waste the copper of the not needed circuit.

What is really needed is far more lightweight EV's that don't need huge battery packs to do 200 mile range! In my 2 seat EV sportwagon because it's made in stronger tham steel medium tech composite can go 240 miles in the same pack the Volt gets 40 miles from as an example simply because it weighs around 1000lbs and very aero.

I really don't see much need in over 100 mile range as an eff ICE generator run at near full speed weighs little and gives unlimited range at over 100mpg in such an EV saving both the weight and cost of a battery pack that will rarely be used.


I'm sure that it would have taken a great amount of effort to make a standard range/dryer plug safe for use by the general public in an outdoor environment, near flammable fuels, and have the ability to withstand many insertion cycles.

The typical receptacles used in a house cannot provide a level of safety, protection, and durability that would be necessary for this environment. So if you have to design a new connector, you might as well design it to meet the needs of the intended application.

Matthew Sell

LOL... a dryer plug? Riiiight. Oh well, on to more serious matters:

Why are onboard ICE generators manufactured of materials as if they're still connected to the drive train? Why aren't they NG-fueled? But most of all, why hasn't somebody realized that a large, aerodynamic EV is what most of the world is waiting for (young families, traveling retirees, taxis, carpooling commuters, the list is endless) while also serving as the perfect platform for in-frame batteries and onboard generators?

Really disappointing that nobody has made these small leaps. Surely, Lee (minivan) Iacocca is spinning in his grave.

Fritz Menzel

dont believe it,the automotive industry missing a chance to create a muliplicity of expensive non compatible components, i hate the needlessly overcomplicated computerc ontrolled modern mashine, purposely designed to be as impossible to work on except by rip off main dealerships, with elastic band timing belts, transeverse crammed in engines,supposedly technical mineral synthetic ridiculously expensive oils, pandering to the green car hating lobby with its lying global warming propoganda saying we are choking to death on nonexistant co2 fumes, its expensive useless catalictic converters, its eloi fluid injection systems which glog up and put the car into crawl mode when you are overtaking, all having to go on their stinking main dealer overpriced computer system. and this is progess, only for them,and the useless volt electric car gone out of production,could have told you pure electric cars would never work, battery technology has not, SIGNIFICANTLY increases since the 1920,s. i would love to put a retro technology car into production with ease of fixability a key selling point, no computer technology, just reliable fixability. does anyone know how the co2 content of a perfectly tuned pre computer pre cat controlled car compares.?

Chris Keane

I stand and wait. An electric car with a range of 250km or 500km to be able to do the return trip on a single charge from my house off peak power. Need to carry or tow a trailer with 2 scooters. Will ordinary people be able to buy the plug to adapt it to the 240v house hold power? We have been ripped off for a hundred years by oil companies. We need nuclear power and very cheap electricity. The rest of the world is not there for the RIPPING OFF. I am ready to buy my electric car and I have the use for it. (petrol is only a compromise). Dont need fuel ingection, dont need 6 speed gear box. Just an electric motor in the wheels and a big battery.


Making a EV specific plug is a task that is not warranted. The products already exist and is readily available. Go down to your local electrical distributor and order up a 240V plug and receptacle and install it into your house. Every house has 240V available and is being used. Yes your dryer and yes your electric heat. If the plug wears out then put a new one on. It is quite easy and should not be this complicated. Why is the industry trying to make it so complicated. EV is also easy. Extended range by putting in a small generator. Easy. What we need to do is stop the comparison between gas and electric and just use electric.

Peter Poburan
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