We estimate at what size electric-vehicle stocks could become constrained by metal availability by assessing metal requirement and availability for nine types of batteries: Li-polymer(V), Li-ion(Mn, Ni and Co), NaNiCl, NiMH(AB2 and AB5), NiCd and PbA, that contain seven potentially scarce metals/group of metals: lithium, nickel, cobalt, vanadium, cadmium, lead and rare-earth elements. We assess metal intensities (kg/kWh), battery energy capacities per vehicle (kWh/vehicle), losses in recycling and manufacturing, stocks of available resources, constraints on annual mine production and competition for metals. With pessimistic assumptions for all parameters the material-constrained stocks of battery electric vehicles range from 1.1 million NiCd-battery vehicles to 350 million NaNiCl-battery vehicles. Optimistic assumptions result in estimates between 49 million (NiCd) and 12 000 million (Li-ion(Mn)) vehicles. The corresponding figures for hybrid electric vehicles are typically a factor of 10 higher. Critical factors that affect the outcome are identified.