Electricity can be used to power plug-in electric vehicles (PEVs), including both all-electric vehicles, also called battery-electric vehicles, as well as plug-in hybrid electric vehicles. These vehicles can charge their batteries by drawing electricity directly from the grid and other off-board electrical power sources. In contrast, hybrid electric vehicles are fueled with liquid fuels, like gasoline, but use small batteries to recapture energy otherwise lost during braking (ultimately boosting fuel economy). PHEVs can use off-board electricity for power, which classifies them as a PEV, but can also use liquid fuels and operate similar to a HEV if necessary. Using electricity to power vehicles can have significant energy security and emissions benefits.