A plug-in hybrid electric vehicle (PHEV) or plug-in hybrid vehicle (PHV) is a type of hybrid electric vehicle equipped with a battery that can be recharged via a power cable to an external electric power source, in addition to charging internally by its on-board internal combustion engine–powered generator. While PHEVs are predominantly passenger cars, there are also plug-in hybrid variants of sports cars, commercial vehicles, vans, utility trucks, buses, trains, motorcycles, mopeds, military vehicles and boats.
Similar to battery electric vehicles (BEVs), plug-in hybrids can use centralized generators of renewable energy (e.g. solar, wind or hydroelectric) to be largely emission-free, or a fossil plant in which case they displace greenhouse gas emissions from the car tailpipe exhaust to the power station. As opposed to conventional hybrid electric vehicles (HEVs), PHEVs generally have a larger battery pack that can be recharged (theoretically) from anywhere with access to the electrical grid, offering enhanced energy efficiency and cost-effectiveness when compared to relying solely on the on-board generator. Additionally, PHEVs can support longer and more frequent all-electric range driving, and their electric motors often have higher power output and torque, are more responsive during acceleration, and, overall, have lower operating costs. Although a PHEV's battery pack is smaller than that of all-electric vehicles of the same weight, as it must accommodate its combustion engine and hybrid drivetrain, it provides the added flexibility of reverting to the use of its gasoline/diesel engine, akin to a conventional HEV if the battery charge is depleted. This feature helps alleviate range anxiety, particularly in areas lacking sufficient charging infrastructure.
Mass-produced PHEVs have been available to the public in China and the United States since 2012, By 2021, BYD Auto emerged as the largest plug-in hybrid vehicle manufacturer in the world. , BYD plug-in hybrid cumulative sales surpassed 3.6 million units. The BYD Song DM line of SUVs contributed over 1.05 million units.
China currently has the largest stock of PHEVs in the world, with cumulative sales of 9.31 million units (including EREV) through December 2024. In 2024, over 76% of global PHEV sales was contributed by the Chinese market. In addition, the five largest producers of PHEVs globally are Chinese manufacturers, which are BYD, Geely, Chery, Li Auto, and Changan. Early hybrids could be charged from an external source before operation. 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".
The July 1969 issue of Popular Science featured an article on the General Motors XP-883 plug-in hybrid. The concept commuter vehicle housed six lead–acid batteries in the trunk area and a transverse-mounted DC electric motor turning a front-wheel drive. The car can be plugged into a standard North American 120-volt AC outlet to recharge.
Revival of interest
right|thumb|[[Lithium-ion battery pack, with cover removed, in a CalCars "PRIUS+" plug-in hybrid converted Toyota Prius converted by EnergyCS]]
In 2003, Renault began selling the Elect'road, a plug-in series-hybrid version of its popular Kangoo, in Europe. In addition to its engine, it could be plugged into a standard outlet and recharged to 95% range in about 4 hours. After selling about 500 vehicles, primarily in France, Norway and the UK, the Elect'road was redesigned in 2007.
With the availability of hybrid vehicles and the rising gas prices in the United States starting around 2002, interest in plug-in hybrids increased. Some plug-in hybrids were conversions of existing hybrids; for example, the 2004 CalCars conversion of a Prius to add lead acid batteries and a range of up to using only electric power.
In 2006, both Toyota and General Motors announced plans for plug-in hybrids. GM's Saturn Vue project was canceled, but the Toyota plug-in was certified for road use in Japan in 2007.
In 2007, Quantum Technologies and Fisker Coachbuild, LLC announced the launch of a joint venture in Fisker Automotive. Fisker intended to build a US$80,000 luxury PHEV with of electric range, the Fisker Karma, initially scheduled for late 2009.
In 2007, Aptera Motors announced their Typ-1 two seater. That company folded in December 2011.
In 2007, Chinese car manufacturer BYD Auto, owned by China's largest mobile phone battery maker, announced it would introduce a production PHEV sedan with of electric range in China in the second half of 2008. BYD exhibited it at the North American International Auto Show in Detroit in January 2008. Based on BYD's midsize F6 sedan, it uses lithium iron phosphate (LFP)-based batteries instead of lithium-ion batteries and can be recharged to 70% capacity in 10 minutes.
thumb|Three plug-in converted [[Toyota Prius recharging at San Francisco City Hall public charging station ]]
In 2007, Ford delivered the first Ford Escape Plug-in Hybrid of a fleet of 20 demonstration PHEVs to Southern California Edison. As part of this demonstration program, Ford also developed the first flexible-fuel plug-in hybrid SUV, which was delivered in June 2008. This demonstration fleet of plug-ins has been in field testing with utility company fleets in the U.S. and Canada, and during the first two years since the program began, the fleet has logged more than 75,000 miles. Sales of the Escape PHEV were scheduled for 2012. but later in the year Toyota indicated they would be offered to commercial fleets in 2009.
On March 27, the California Air Resources Board (CARB) modified its regulations, requiring automobile manufacturers to produce 58,000 plug-in hybrids during 2012 through 2014. This requirement is an asked-for alternative to an earlier mandate to produce 25,000 pure zero-emissions vehicles, reducing that requirement to 5,000. On June 26, Volkswagen announced that they would be introducing production plug-ins based on the Volkswagen Golf compact car. Volkswagen uses the term 'TwinDrive' to denote a PHEV. In September, Mazda was reported to be planning PHEVs. On September 23, Chrysler announced that they had prototyped a plug-in Jeep Wrangler and a Chrysler Town and Country minivan, both PHEV with series powertrains, and an all-electric Dodge sports car, and said that one of the three vehicles would go into production.
On October 3, the U.S. enacted the Energy Improvement and Extension Act of 2008. The legislation provided tax credits for the purchase of plug-in electric vehicles of battery capacity over 4 kilowatt-hours. The federal tax credits were extended and modified by the American Clean Energy and Security Act of 2009, but now the battery capacity must be over 5 kWh and the credit phases out after the automaker has sold at least 200,000 vehicles in the U.S.