ROCHESTER, Minn. — The City Council tentatively approved a uniform rate for charging electric vehicle at all public kiosks: 17 cents per kilowatt hour. There also would be a $5 hourly fee for cars left parked too long at a kiosk. Kayla Betzold, the city sustainability coordinator, said the current rate structure has failed to recognize that vehicles have different sizes of batteries. Her recommendation reflected a survey of 34 cities.