Passenger cars are responsible for a large and steadily growing share of global energy-related greenhouse gas (GHG) emissions. Electric vehicles (EVs) powered by renewable electricity have the potential to provide a substantial contribution to the decarbonization of passenger car transport. Unless carbon capture and storage technologies become cost competitive, EVs are likely to form a growing share of the personal mobility solution. But what is the lowest cost path to achieving high levels of EV penetration? Encouraged by the falling cost of batteries, EV policy today focuses on expediting electrification, paying comparatively little attention to the cost of the particular type of EVs and charging infrastructure being deployed. This paper argues that, due to its strong influence on EV innovation paths, EV policy could be better designed if it paid more attention to future cost and technology development risk.