Most electric vehicles contain batteries that are charged from an external power source. The exception is a hydrogen fuel-cell vehicle (FCEV), which is also an electric vehicle, but uses a battery that is charged from an onboard source, namely a hydrogen fuel cell.
Although hybrid vehicles and FCEVs also contain a battery, the term ‘battery electric vehicle’ or BEV is commonly used to denote vehicles that only use a battery (as opposed to a hybrid or FCEV that also uses a combustion engine or fuel cell). This story focuses on BEVs exclusively.
Once the battery in a BEV is charged, it is connected to an electric motor which sends torque to the wheels. Many electric vehicles typically use one motor that sends torque to either the front or rear wheels. However, several EVs such as versions of the Tesla Model 3 and Y use dual motors to provide all wheel drive. Some higher performance BEVs can have as many as four electric motors. As an extreme example, the Rimac Nevera features four electric motors that drive each wheel individually.
Regenerative braking and single-pedal driving
Regenerative braking is an efficient way for an electric vehicle to slow down, especially in urban, stop-start environments. When the driver releases the accelerator pedal or uses the brakes, the electric motor switches direction and acts as a generator, with the wheels working as a crank. This system allows a portion of the kinetic (movement) energy from the wheels to be captured, converted into electrical energy and stored in the electric vehicle’s battery.
Some electric vehicles also offer a feature called single-pedal driving. When this is enabled, the electric vehicle will progressively use a combination of regenerative and mechanical braking to bring the car to a complete stop, as soon as the driver begins to release the accelerator pedal. Some vehicles will also apply the parking brake automatically once the vehicle is stopped, to ensure it does not continue to creep or roll.
For more information on regenerative braking and single-pedal driving, please see our earlier story here.