Range extender (REx): What does it mean?

An electric car with a small engine that acts as a generator.

Range extender (REx): The long answer

In the UK, a range extender (REx) is a term commonly used in the context of electric vehicles (EVs). A range extender is essentially a small internal combustion engine (usually petrol or diesel) that works alongside the electric motor in an EV. Its primary purpose is to generate electricity to power the electric motor and recharge the vehicle's battery.

The range extender helps address one of the main limitations of fully electric vehicles - their limited driving range. While EVs rely solely on their battery packs for power, which can have a limited range, a range extender provides an additional source of electricity, effectively extending the distance the vehicle can travel before needing to recharge.

When the battery level in an EV with a range extender drops to a certain point, the engine kicks in to generate electricity, allowing the vehicle to continue driving. This provides drivers with the peace of mind that they won't be stranded with a depleted battery, as they can rely on the range extender to keep them going until they can access a charging point.

The presence of a range extender in an EV can significantly increase its overall range, making it a more practical option for longer journeys or areas with limited charging infrastructure. It offers drivers the benefits of electric driving, such as reduced emissions and quieter operation, while providing the flexibility of an internal combustion engine when needed.