Electric Vehicle Supply Equipment—Not So New

Electric Vehicle Supply Equipment—Not So New

This piece was originally published in the July 2017 issue of electroindustry.

Bryan P. Holland, Southern Region Field Representative, NEMA

The 1996 edition of the National Electrical Code® (NEC) included for the first time an article dedicated to electric vehicle (EV) charging requirements, leading some to believe that the industry began in the 1990s. Actually, it originated in the mid-1800s as one of the first markets for electric motor, storage battery, and distribution equipment manufacturers.

Between 1834 and 1896, small-scale production of EVs encouraged interest. EVs could outperform steam- and gas-powered automobiles. The first car dealership in the United States sold only EVs, and the first auto race in the nation was won by an EV. By 1900, large-scale production ushered in a golden age; by 1917, more than 40,000 EVs were on the road; and by 1920, there were several EVSE manufacturers, 700 charging stations, and unfortunately, 38 separate charging plug configurations.

Early manufacturers adopted the “slow-speed” motor. The 80V motors operated at 800 to 900 rpm and could push a 700-pound to five-ton vehicle up to 30 mph. The most common storage battery was standard lead-acid, the largest manufacturer of which was the Electric Storage Battery Company. The other was the Edison alkaline storage battery, which cost twice as much but had superior performance. It had a life of about 9,000 miles through rectified charging methods, requiring eight-to-12 hours of charging time.

EV supply equipment (EVSE) in the early 1900s included direct current (DC) charging from a 110–220 VDC source or alternating current (AC) from a 500–600V source. The most common AC rectifiers were motor generators, rotary converters, and mercury arc rectifiers.

Before the 1996 NEC, requirements for EVSE were scattered throughout the code. Section 5109 of the 1937 edition included requirements for battery charging. The 1947 NEC revised the title to Electric Vehicle Charging and moved the rules to Section 5133. In subsequent editions, EV charging was in Section 5105.h, Section 511-8, and finally Section 511-9 of the 1993 NECArticle 625 of the 2017 NEC has four parts, 23 articles, and 20 definitions.

Rapid development of the gasoline-powered vehicle, the lack of electrical infrastructure outside of cities, and the great depression brought an end to the first golden age. Many enthusiasts claim we are in the second golden age. An estimated 625,000 EVs are on the road today, using more than 70,000 charging stations. The availability, speed, and convenience of EV charging must be comparable to fueling gas-powered vehicles for the industry to fully disrupt and overtake the transportation industry.

In the article “Seeing Ahead for the Electric Vehicle,” in the February 1917 issue of Electric Vehicles Magazine, Thomas Edison said:

The growth of the electric vehicle has been hindered by lack of charging facilities. It’s a funny business when so few central stations realize that there is a market for the sale of current for charging electric cars. The public is in a curious position of wanting to buy something for which there is no place to go….Sometimes I think the men who ought to see ten years ahead see only to next week.

These sentiments hold true today.


NEMA represents manufacturers of EVSE products and assemblies in their efforts to develop the market by educating the public on features and value. Learn more at www.nema.org/EVSE.


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