Porsche is getting its dealerships on board with selling electric cars, in preparation for its upcoming Mission E electric sedan, by insisting that each of the company's 189 U.S dealerships install fast charger with enough juice to charge the car's big, 300-mile battery to substantially full in just over 20 minutes.

Presumably during this time, the Mission E driver is perusing leather keychains, embroidered jackets, and string-back gloves in the showroom—or even pondering another new Porsche—perhaps a Cayenne eHybrid.

Porsche Mission E Cross Turismo concept

Porsche Mission E Cross Turismo concept

Porsche has said that it will deliver the big Mission E sedan by 2020, and have followed with a concept of a Mission E Cross Turismo, which looks a lot like a Panamera Sport Turismo with a 300 mile battery. Dealerships should have the chargers by the time the Mission E goes on sale in 2020.

In addition to the 189 fast chargers at dealerships, Porsche executives told Automotive News that the company would be partnering with other charging networks to give Mission E drivers access to 500 fast chargers across the country (apparently counting those in its dealerships.)

DON'T MISS: Electrify America maps out charging network to rival Tesla Superchargers

By far the most likely of those networks is the one being built by Electrify America, with funding from the Volkswagen diesel settlement.

Electrify America plans to roll out 2,000 fast chargers at 484 locations across the country by the end of next year. Of those more than a handful will be liquid-cooled 350-watt stations. Porsche is owned by the Volkswagen Group in Germany.

CHECK OUT: Porsche Mission E Cross Turismo concept

Even though Porsche electric car drivers will have access to these additional fast chargers, the electricity may not be free, Porsche North America CEO Klaus Zellmer told Automotive News. Electrify America says its stations will be credit-card operated, though some automakers may also provide limited free access cards.

Zellmer says that 500 chargers around the country is what Mission E drivers should need to go about their business without range anxiety.

Others, such as Electrify America, think there need to be considerably more.