A plug-in hybrid electric vehicle (PHEV) is a hybrid electric vehicle whose battery can be recharged by plugging it into an external source of electric power, as well by its on-board engine and generator. Most PHEVs are passenger cars, but there are also PHEV versions of commercial vehicles and vans, utility trucks, buses, trains, motorcycles, scooters, and military vehicles.
Mass-produced plug-in hybrids were available to the public in China and the United States in 2010. By the end of 2017, there were over 40 models of series-production highway legal plug-in hybrids for retail sales. Plug-in hybrid cars are available mainly in the United States, Canada, Western Europe, Japan, and China. The top-selling models are the Mitsubishi Outlander P-HEV, the Chevrolet Volt family, and the Toyota Prius PHV.
The Lohner-Porsche Mixte Hybrid, produced as early as 1899, was the first hybrid electric car. Early hybrids could be charged from an external source before operation. However, the term "plug-in hybrid" has come to mean a hybrid vehicle that can be charged from a standard electrical wall socket. The term "plug-in hybrid electric vehicle" was coined by UC Davis Professor Andrew Frank, who has been called the "father of the modern plug-in hybrid".
With the availability of hybrid vehicles and the rising gas prices in the United States starting around 2004, interest in plug-in hybrids increased. Some plug-in hybrids were conversions of existing hybrids; for example, the 2004 CalCars converision of a Prius to add lead acid batteries and a range of up to 15 km (9 mi) using only electric power.
In 2006, both Toyota and General Motors announced plans for plug-in hybrids. GM's Saturn Vue project was cancelled, but the Toyota plug-in was certified for road use in Japan in 2007.
On December 15, 2008 BYD Auto began selling its F3DM in China, becoming the first production plug-in hybrid sold in the world, though initially was available only for corporate and government customers. Sales to the general public began in Shenzhen in March 2010, but because the F3DM nearly doubles the price of cars that run on conventional fuel, BYD expects subsidies from the local government to make the plug-in affordable to personal buyers. Toyota tested 600 pre-production Prius Plug-ins in Europe and North America in 2009 and 2010.