A little discussed area that has a lot of importance is how electric cars will interface with the grid.

Yes we are aware the driver will attach an electric cord from the wallbox to the car, but at issue is exactly how that cord will fit into the car.

The specification that is gaining steam is called SAE J1772 and it refers to the coupler shown above.

People will charge their cars either with 110 or 220 V electric lines, and some cars in the future may even accept higher voltages. Current will also vary from 8 amps in the case of the Volt at 110 V to up to as high as 70 amps or greater. There will also be public charging stations to deal with. Since the far end of the cord will thus have many different plugs it is important to keep end that goes into the car the same.

GM notes at next week's meeting of the Society of Automotive Eng inners, there is actually a Task Force that will convene to continue its work in trying to make SAE J1772 the industry standard.

GM Engineer Greg Kissel writes "You’re already aware we’re working to make the Volt as efficient as possible, but we’re also helping lead the standardization of this plug and how you interact with it as well as the electrical grid." He notes that once this standard is adopted it will be required in all electric cars regardless of brand or maker.

Source ( GM )