For some time, vehicle electrification comprised of little more than the 12-volt rechargeable battery used to start a motor vehicle. Its main purpose is to provide electric current to the electricity powered starter motor, which in turn starts the conventional internal combustion engine. Once the engine is running, power for the vehicle’s electrical systems is still provided by the battery, with the alternator charging the battery as demands increase or decrease.
The 1990s saw the introduction of the first mass produced hybrid vehicle using a combination of a conventional engine and an electric motor/generator, fitted within the transmission. This type of vehicle allows for an improved miles per gallon ratio and reduced CO2 emissions, where the electric motor takes load away from the engine by assisting during acceleration and, over short distances, propelling the vehicle with the electric motor only. This requires additional energy to power the electric motor, so the introduction of an additional high voltage battery was necessary, complete with its accompanying wiring and components.
One benefit of electric motors is regenerative braking, which turns the electric motor into a generator when cruising or braking to capture otherwise wasted energy. This is then stored in a small high voltage battery for later use. These vehicles still retain their 12-volt batteries and components for comfort and convenience features.
The past 20 years have seen a gradual increase in electrified vehicle types, with their electric components and variable operating voltages. For example, mild hybrids use starter/generators and 48-volt batteries to improve miles per gallon and CO2 emissions, while also supporting the conventional 12-volt system.
Plug-in hybrids, with large high voltage batteries, extend the electric-only range of these vehicles while still retaining a conventional engine. Finally, Battery Electric Vehicles deliver electric only propulsion and, in theory, zero emissions.
Looking to the future, hydrogen powered vehicles are expected to become more prevalent once the infrastructure is ready to support them. Electrification still plays a major role within these vehicles as an electric motor propels them.