How is a plug-in hybrid different than a regular hybrid?
Hybrid electric vehicles (HEVs) have a gasoline engine that is assisted by a battery-powered electric motor. The battery in a hybrid is charged by recapturing energy from braking and deceleration. In a plug-in hybrid (PHEV) a lithium-ion battery is added to the HEV system. The additional battery is charged only from an external source by plugging in. The lithium ion battery supplements the electrical storage capability of the original HEV battery. After converting your hybrid into a PHEV, when you plug in your car, you are charging only the newly installed battery. The lithium ion battery drains while you drive, assisting the gas engine, often times replacing engine use entirely. Plug-in hybrids use more electric power from the battery for driving and therefore consume less gasoline. After the plug-in battery is fully depleted, the PHEV behaves like the original factory hybrid until you charge the battery again by plugging it in.
