 After developing 10 prototypes for research and development purposes, in May 2013 Audi decided to cancel production of the electric car due to its limited all-electric range as battery technology had not advanced as quickly as Audi had expected, making the R8 e-tron unviable for series production.In March 2014 Audi revised its decision and announced it will build the R8 e-tron upon request.The carmaker explained that their latest development work resulted in an increased range from to approximately .