Longer than to refuel a Hydrogen fuel cell vehicle . Toyota were quoting refueling for 300 mile range in 5 minutes or less, which seems real world practical , even if as Elon states the end to end efficiency of a pure electric is higher. Different approach, different trade offs, pick the one that best fits your use case. I could see it being more practical for people without a dedicated garage / parking space / overnight charging point. Needs a more pervasive infrastructure, and more economies of scale. Ubiquitous fusion power would help both camps. http://www.bbc.com/news/business-33005362 http://evobsession.com/hydrogen-cars-vs-electric-cars-detailed-comparison-efficiency/