Hybrid cars use multiple sources of energy: A petrol or diesel engine works together with an electric motor to propel the vehicle. This allows the vehicle to burn less gasoline, resulting in better fuel efficiency compared to conventional fuel-only engines. The electrical power helps to increase the performance of the engine. Except for plug-in hybrids, in hybrid products, the battery is charged through the vehicle's own system. So you don't need to charge the vehicle yourself. Plug-in hybrids are halfway between conventional cars and fully electric vehicles. These cars are powered by both an electric motor and an internal combustion engine, but their batteries are charged by connecting to an external electrical source (“plug-in”).