Regenerative braking
Regenerative braking is used by all four types of electric vehicles for battery charge. When braking, the engine continues to rotate even though the car is trying to slow down. The energy is captured with regenerative braking, otherwise, it is lost while producing electricity that charges the battery.
Mild Hybrid and Hybrid
There are two ways hybrid vehicles can be charged:- Regenerative braking and conventional combustion engine. The internal combustion engine drives the generator, which converts mechanical energy into electrical energy to charge the battery.
Plug-In Hybrid
The charging can be done by connecting the large battery to the power grid. Once the battery is empty, the vehicle behaves like a conventional hybrid with an internal combustion engine that runs on demand.
Fully electric vehicle
Exclusively, all-electric vehicles are powered, and they have no combustion engine. The battery can be charged by connecting it to the mains.
Source: Ford.de.