The market for electric-car batteries could reach $25 billion in 2020.But formidable challenges remain. No clear winner has yet emerged amongbattery technologies, and battery makers are unlikely to meet the USABCtarget cost of $250 per kWh by 2020. Governments will need to provideextensive support for technology development, battery-charginginfrastructure, and subsidies for consumers’ purchases of electricvehicles. OEMs may partner with cell makers before turning to tier-onesuppliers to furnish batteries as the latter become commodities.