Why Don’t Electric Cars Have Alternators? (Explained)

Alternators play an important role in converting waste rotational energy into electrical energy.

There’s a bit of misinformation floating around about why electric cars don’t have alternators.

Let’s explore the main reasons why electric cars don’t have alternators.

Electric Cars Don’t Have Additional Rotational Energy to Waste

The main purpose of an alternator is to convert the waste rotational energy into electrical energy. ICE has a large amount of rotational energy, which is ideal for running the vehicle. However, this is not the case for electric vehicles.

These cars are designed to utilize all the rotational energy and would not have wasteful power that needs conversion.

The manufacturers of electric cars have ensured high levels of efficiency. Their main goal is to eliminate carbon and facilitate using renewable energy sources. Hence, the minimization of waste is one of their key components.

Energy conversion through an alternator is wasteful.

Energy is lost during the conversion process, which contradicts the design of electric vehicles to save energy. Therefore, alternators wouldn’t be ideal for use on these vehicles.

The alternator loses approximately 40% to 45% of energy through heat, vibrations, and noise.

Electric Cars Have Enough Electrical Energy to Operate

As mentioned above, an alternator converts rotational energy into electrical energy. Electric vehicles require the conversion of electrical into mechanical energy for them to operate smoothly.

Therefore, an alternator would not be useful in these vehicles.

Electric vehicles use an electric motor that converts energy by creating an electromagnetic field within a coil positioned in the magnet.

The magnetic energy created causes a rotational force on the coil, thus producing the mechanical energy needed to run the vehicle.

In the case of internal combustion engine cars, the alternator produces electrical energy converted to DC to facilitate the vehicles functioning. The additional energy for the car is derived from the 12V battery.

The battery gets its charge from the alternator when the engine is running.

The electricity supplied by the 12V battery is not enough to serve the necessary function in an ICE. Therefore, the alternator acts as a supplementary supply source.

The alternator also ensures that other parts of the ICE which require electric energy have enough supply.

Such is not the case for electric vehicles because they are designed to use electric energy.

Therefore, the vehicle already has enough energy in its inbuilt system and would not need an additional supply. Hence, using alternators in these vehicles would have no engineering meaning.

Alternators Would Cause Inefficiencies in EVs

Another main reason why an electric car doesn’t need alternators is the need for efficiency.

These vehicles are designed to use electric power.

Therefore, using electricity to produce electricity would be a waste of energy. Therefore, the device would create unnecessary inefficiencies.

An alternator keeps the 12V battery charged. In the case of electric vehicles, this isn’t a major necessity because these cars have a more efficient alternative for keeping the battery charged.

The electric cars have a DC to DC converter, which substitutes the need for an alternator. Note: Electric cars run on AC motors.

The device converts energy from the main battery pack to the 12v battery.

Hence, there is no need for an alternator.

Electric Cars Don’t Have an Engine

Electric cars don’t need an alternator because they have no engine but run on a motor.

An alternator requires mechanical energy to perform its function. The energy is obtained from the engine’s capacity to burn fossil fuel.

Since an electric car doesn’t have an engine that burns fuel, installing an alternator would be a waste of resources.

In this case, the electric motor would run a device to make electric energy, a process that makes no sense.

Using the motor to use the necessary energy would spend more electric energy than it makes.

If the alternator could create more energy, it would create a perpetual motion machine, which is not necessary for electric cars. These vehicles’ batteries only pack approximately 300V, and a 12V system is needed for the radio, headlights, and other accessories.

Alternators provide an expensive means of converting energy from one form to another.

In an electric vehicle, energy only needs conversion from one voltage to another.

The good news is that these vehicles have a simpler and cheaper way of doing so. DC converters have proven to be more effective than alternators because they don’t waste energy.

While these converters require a current to convert the energy, they minimize losses due to the absence of vibrations and noise.

They also have a cooling system to minimize energy loss through heat.

DC Converters Require Less Maintenance Than Alternators

DC converters are widely used in electric vehicles to convert electric energy into the required voltage.

EV manufacturers prefer them to alternators because they require less maintenance. These devices are compact and lighter than alternators.

They don’t have moving parts like:

  • pulleys,
  • belts,
  • or bearings.

These parts are prone to damage and would require regular maintenance. Hence. Their absence means your vehicle’s DC convertor would require minimal maintenance.

Using alternators on electric vehicles would be complicated, which means additional installation costs.

They require a lot of maintenance and, therefore, aren’t an ideal option. EVs aim to enhance sustainability, which isn’t achievable with alternators. No one wants to pay extra amounts for car maintenance, a factor that makes EV an ideal choice of vehicle.

Regenerative Braking Utilizes Additional Energy

Internal combustion engine vehicles have a lot of rotational energy which is not utilized by the car.

Such is not the case for electric vehicles because the only rotational energy is created in the wheels as the car slows down.

The manufacturers of electric vehicles understood the possibility of energy wastage through this process. However, they implemented the concept of regenerative braking to utilize the excess energy.

The concept increases the vehicle’s range by reducing the energy demands in the motor.

Regenerative braking harvests the waste rotational energy while the car is slowing down and converts it to electrical energy. In turn, the energy is sent back to the battery for later use in driving.

The drive wheel motors in electric vehicles rotate in two directions to facilitate regenerative braking.

The motor rotates forward when you step on the accelerator, causing the wheels to move forward.

As you step on the brake pad, the motor changes its rotation direction to utilize the additional electric energy.

In this situation, the electric motor functions as the alternator. Therefore, there is no need to use alternators in electric vehicles because their functions are already covered.

An electric motor is also larger and more effective than alternators, thus making them a non-essential component for use in electric cars.

The regenerative braking varies from one electric vehicle to another. The driver or car owner can adjust it depending on their driving preferences and conditions. For instance, in Tesla, the braking is light to facilitate forward motion as much as possible.

The rotational energy in the axle is used to power the car to move forwards. Therefore, introducing an alternator would interfere with the energy’s effectiveness in powering an EV.

The device would slow down the car.

While some mechanics might add an alternator to electric cars, it wastes time because the cumulative result is energy waste. This isn’t something you want for your car.

Commercial EVs will never use alternators in their vehicles because they understand the inefficiencies they cause in the designs of these automobiles.

General Pros and Cons for Alternators in EVs


  • They would have enhanced efficiency at high speeds


  • Electric cars don’t have additional rotational energy to waste
  • Electric cars have enough electrical energy to operate
  • Alternators would cause inefficiencies in EVs
  • Electric cars don’t have an engine
  • DC converters require less maintenance than alternators
  • Regenerative braking utilizes additional energy

What Do Reviews Say

Electric vehicles have enough charge in the battery pack and don’t need alternators. Alternators use electric energy to create the same energy, so their use would be a waste of resources. EVs have different charging connectors that ensure the vehicle is packed with enough charge within a specific time.

“There are also different types of connectors used, but most importantly, there are different levels of EV charging that determine how long it takes to charge an EV.”

(Source: Forbes .com)

Electric vehicles don’t need additional energy creation like in the case of internal combustion engine cars.

A fully charged battery pack would go for miles without requiring a recharge.

Hence, alternators aren’t a priority for these vehicles.

“A full charge can cover a range of some two hundred and fifty miles, which is more than enough for ninety-five percent of the trips I make in a year.”

(Source: Newyoker.com)

Final Thoughts

Electric vehicles have been on the market for a while. However, there is no practical application of alternators in the manufacturing process.

An alternator is a reliable device for converting rotational to electric energy.

The only challenge is that using them in EVs would introduce major inefficiencies, affecting the vehicles’ effectiveness.

Therefore, DC converters are the best option.





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