Electric Cars Need a Plug Standard

No Clear Winner in Fight for Plug Dominance

All major automakers are developing battery-powered cars, but electric vehicles have been hindered, at least in reputation, by their limited range, premium cost and general lack of fast-charging stations. To make matters worse, charging methods are fragmented and different regions adopt different standards. At this point, it’s not clear which charging specification will dominate the market, but as we’ve learned from wireless charging solutions, for an infrastructure to be successful, there can’t be fragmentation.

In late 2017, German car-makers BMW, Daimler and Volkswagen together with Ford, announced plans to build out a network of 400 charging stations for electric vehicles in 18 European countries, based on the Combined Charging System method. The group expects this infrastructure to set an industry standard, giving these companies an edge over electric car rivals. Tesla and Japanese manufacturers use different plugs and communication protocols to link batteries to chargers.

Independently-owned electric charging points support several types of standard, with SAE J1772 providing quicker AC level 2 charging, and the Combined Charging System offering DC fast charging. A fast-charging protocol known as CHAdeMO has been popular with most Japanese automakers, but its future could be threatened by the growing popularity of the Combined Charging System. The latter gets its name from the fact that it brings together AC and DC charging options in one plug.

Another major charging technology for electric cars is Tesla’s Supercharger, which uses its own standard to support charging levels 1, 2, and 3 on the same connector. This currently has a capacity of 145 kW, but it caps the power it distributes to a vehicle at 120 kW. The Combined Charging System can deliver a maximum of 200 kW, although no station currently offers that kind of power, nor is any electric car able to receive it. However, it does provide room for improvement for future vehicles, including a path to a 350 kW power output that could charge a long-range vehicle in less than 10 minutes instead of an hour on the best DC fast-charging stations.

China is pressing ahead with its own protocol, called GB/T 20234. The country has ambitious quotas for sales of electric cars, so most major manufacturers are also ensuring their vehicles for this market are compatible with this technology. However, there’s hope that the country will also adopt one of the other standards at some point.

According to the China Electric Vehicle Charging Infrastructure Promotion Alliance, there are over 170,000 GB/T charging stations in the country already. In comparison, it’s reported there are about 7,000 Combined Charging System points, more than 16,000 CHAdeMO outlets and around 8,500 Tesla Superchargers. It’s hard to see how these three fragmented standards outside China can all survive. Perhaps it’s only a matter of time before the Combined Charging System and CHAdeMO have to merge.

It’s also a question of economics. Companies building charging stations say the number of plug formats will need to be lowered to keep costs down and to remove obstacles for current and potential electric car owners. Charging involves a complex set of plug sizes and terms, and energy needs to be put into making it simpler for consumers.