Between 2010 and 2012, car manufacturers are planning to introduce dozens of models that are either partially or completely powered by rechargeable batteries. Plug-in hybrid vehicles like the Chevy Volt, which will have a gasoline engine to fall back on after about 40 miles, will take up to eight hours to charge on ordinary 120-volt household current; some all-electric vehicles, with larger batteries designed to provide a range of 100 to 200 miles, will need 10 to 12 hours.