An auxiliary power unit, usually a compact gasoline or diesel engine, that acts as an onboard generator for a battery electric vehicle. Unlike a traditional hybrid setup, the range extender has no mechanical connection to the drive wheels. It runs at a steady, efficient RPM to supply electrical power to the traction motor or recharge the battery pack once the plug-in charge is depleted.
The i3 has a two-cylinder range extender that kicks on automatically when the battery drops to about six percent.
Vehicles with range extenders often have artificially small fuel tanks to comply with regulations that classify them primarily as zero-emission vehicles.
Also heard as
- REx
Related terms
EV
An electric vehicle uses one or more electric motors for propulsion instead of an internal combustion engine.
PHEV
A plug-in hybrid electric vehicle combines a combustion engine with a grid-chargeable battery pack.
Range anxiety
The psychological stress experienced by drivers fearing their electric vehicle will run out of battery before reaching a charger.