Unlike internal combustion vehicles that run on gas, electric cars do not have an alternator.
Instead, they implement DC converters to keep the 12-volt battery for accessories powered. Even hybrid powertrains include an integrated starter/alternator system (ISA) to transfer power from the engine to the battery without using a stand-alone alternator.
What does an alternator do?
A car’s alternator is a way for the vehicle to generate enough electricity to keep the 12-volt battery alive as it drives. This requires mechanical power from the engine and a fuel source, of course. A serpentine belt transfers the engine’s energy to the alternator by converting mechanical energy to electrical energy.
How do alternators work?
Alternators work by moving direct current through copper wire coils or permanent magnets. This flow creates a magnetic field that alternates the polarity. Hence the name “alternator,” as it is alternating current.
In the 1960s, alternators replaced DC generators, which were the more efficient solution. However, the alternator has become an inefficient and high-maintenance component in the face of electric vehicles and DC converters.
Do electric cars have alternators?
Electric cars do not have alternators. Instead, they have DC converters, which act as an alternator, requiring charging. This is one reason you must plug your electric vehicle in when the battery is low.
DC converters are often a better solution for generating electricity than alternators, as they are more efficient and don’t require gas to function.
Why don’t electric cars have alternators?
You’re not alone if you’re wondering why electric cars don’t have alternators. Internal combustion engines, or ICEs, run off gasoline. A serpentine belt translates the engine’s motion to the alternator, which powers the battery as the car operates.
Since electric vehicles don’t have an internal combustion engine, there’s no power source from which to draw momentum.
If alternators were installed in electric vehicles, they would require more energy to power than they would produce. Effectively, they would just become a drain on the power source, rather than a boost.
When comparing internal combustion engines and electric batteries, the difference is clear: the creation and transmission of power are vastly different from one platform to the next.
Electric cars do not have alternators because they do not need to convert mechanical energy into electrical energy to feed the 12-volt battery so that the car stays running.
Instead, DC converters spit out a different voltage to power the 12-volt necessary to keep various accessory functions working, even after the car has stopped.
For example, a higher current translates to a lower voltage, and a lower voltage corresponds with a higher current.
An Israeli startup company called Electreon wants to turn the road electric cars drive on into a portable wireless charging station. This startup aims to build a road in Michigan that would talk to the charging pad beneath the vehicle via magnetic frequencies to wirelessly charge it as it drives down the road.
Do Tesla cars have alternators?
Teslas do not have alternators. They have DC converters that allow them to convert the electrical energy of the main battery to the correct voltage for the 12-volt battery.
Do hybrid cars have alternators?
Hybrid vehicles typically run off a system that partners the internal combustion engine with a smaller electric battery. This system is called an integrated starter/alternator system, or ISA.
The small electric battery works to recharge the engine as it is performing. Some hybrids use the drive wheel electric motor as an alternator, similar to the concept of regenerative braking.
What are the benefits of a DC converter?
DC converters are compact and lightweight when compared to an alternator. They are much more efficient, though they still lose some energy as dictated by the laws of thermodynamics.
However, DC converters have fewer moving parts (actually none!) and are relatively maintenance-free. These characteristics make them a prime candidate for electric vehicles.
Summary
Alternators convert the energy created by an internal combustion engine into current that charges the car’s 12-volt battery.
Electric and hybrid cars have different fuel systems, so they don’t have an alternator.
Instead, EVs and hybrids incorporate an integrated starter/alternator system (ISA) or a DC converter. This allows them to convert the energy of the larger electric battery to support the car’s 12-volt battery.