The most enduring concern in the electrified vehicle market is range anxiety, which is the worry that an electric car will die before the driver reaches her destination. As battery costs drop and battery range increases, car makers are addressing a bigger concern: Once a driver makes it to a charging station, can she plug in? 

Three years into the age of electrified vehicles, there are three different standards to charge those vehicles. There are also three different levels of charging.

No wonder car buyers are hesitant. To address this, the U.S. Department of Energy and the Joint Research Center of the European Commission launched the EV-Smart Grid Interoperabilty Center at Argonne National Laboratory in Lemont, Ill. earlier this month. The Center, one of three in the world, aims to standardize equipments and harmonize policies to support the global mass adoption of plug-in vehicles.

A harmonized industry, and the grid that powers it, would lead to greater consumer confidence, and forestall a VHS versus Betamax type showdown for the electrification of vehicles. It took decades for a gas stations infrastructure. The difference for electric charging is they can be located anywhere there is power, require less capital per charger and can be built off of existing structures.  

To understand the nascent infrastructure, let’s first address the different charging levels.

Level 1 AC charging can be done on a standard residential outlet of 120 Volts with a maximum of 12 amps. It requires nothing extra on your part except an outlet that can reach your car and a bit of patience.  Level 1 AC can take 8- 12 hours.

Level 2 AC charging, that odd-shaped three prong plug for dryers or water heaters, can fully charge an electrified vehicle in about three hours. The 208 to 240 Volt AC charge typically requires residential installation, which can be provided by automakers or electric vehicle supply equipment (EVSE) companies like ECOtality.

The San Francisco-based company has installed 8,300 Level 2 residential chargers to date. ECOtality offers a suite of Blink HQ chargers, starting at $699 according to spokesperson Kimberly Setliff. Since free public charging will be going the way of Napster, ECOtality offers a $100 charging credit on the Blink Network of over 4,000 publicly available chargers.

 95 percent of charging takes place at home, says Brad Berman, editor of Plug-In Cars, and owner of a 2011 Nissan Leaf. “In two years, I’ve used quick charging three times,” he says.  

Interestingly, the showdown in electric vehicle charging protocol is at the DC quick-charge level. DC quick charging can charge a battery up to 80 percent in under 30 minutes. After that 80 percent mark, the direct current slows down so as not to damage the battery.

“It’s not cost effective, practical or convenient to put a DC charger in your home,” Keith Wilson, the project manager of technical programs at the Society for Automotive Engineers (SAE), says. In the public realm, however, a DC charging infrastructure may be the greatest boost to overcome hurdles in negative public perception.

There are three competing quick-charging standards.


The trade name CHAdeMO is a DC quick-charge protocol originated in Japan and used in the Nissan Leaf, Mitsubishi MiEV and a few others. CHAdeMO was the first to issue a global standard, and has reaped the benefits of being first. Most, if not all, public and private quick chargers around the world are CHADeMO standard. Nissan recently announced plans to add 100 new fast chargers nationwide to its existing 24 west coast chargers.

The knock against CHAdeMo is that you need two battery ports, one for AC charging and one for DC quick charging. The door, or envelope, that houses the chargers is the size of a breadbox, instead of the typical size of a fuel door. It costs automakers more money in unique tooling and space, which is a premium, says Wilson of SAE. “If they can reduce that size down, the cost for tooling and space allocation go down,” says Wilson, who backs the combo coupler.

SAE Combo Coupler

Agreed upon by eight U.S. and European automakers (and the Interoperability Center), the combo coupler incorporates AC Level 1, Level 2 and DC quick-charging on one bulky charger. You wouldn’t be using two charges at once and you wouldn’t opt for AC if DC were available, of course. But the logic is that it’s all right there in one port, so if DC is unavailable you can use AC and you’d never need to lug around adaptors or worry about connectivity.

But SAE was late to the game, announcing a standard in fall 2012 with full agreement from 306 representatives across the spectrum of electrification, power utilities, EVSEs, scientists, government and automakers. There’s a cost to consensus. All the quick chargers currently in the public realm are CHAdeMO.

“There were opposing forces against a path that already existed," Wilson says of CHAdeMO. "Yet there was a strong force that wanted something that was more flexible, condensed."

One automaker uses its own standard.