Alternator Function

What Does a Car Alternator Do?

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It can be annoying when you turn on your car, and the dash light dims, the radio goes out, and the engine dies. These are the first-hand signs that your car alternator is bad. The battery may rev up your car initially, but it is the alternator that produces and continues to supply torque to all the electrical components and your vehicle’s battery.

A Car Alternator is one of the primary electrical generators in your car. It has a stator, rotor, voltage, and other components to the Alternator as well. The Alternator is an essential component of a car. Its presence is critical to the powering of a vehicle, and it’s responsible for the continued running of the car when it starts. If you don’t know what the Alternator does in the car, this article is for you. Keep reading!

What Is A Car Alternator?

The alternator is one of the three primary electrical generators in your car. It is located in the first part of the engine and is driven by the crankshaft.

The alternator consists of a stator and rotor, voltage adjuster, diodes, and a fan for cooling.

  • Voltage Regulator: It regulates the voltage range, thus preventing abnormal power increases.
  • Cooling Fan: It distributes the heat produced during the generation of energy, which prevents the other components of the alternator from overheating. 
  • Diodes: Because the battery cannot work with alternating current (A.C), the diodes convert it to direct current. This allows the current to travel in one direction.
  • Stator and Rotor: These are magnets located in the alternator, and their twirling action creates the alternating current (A.C) that transforms energy into electricity. 

What Does A Car Alternator Do?

Below are some of the functions of an alternator in your car:

  • Recharges the Battery

The primary function of the alternator is to recharge the car battery. The alternator powers the battery by generating an electric charge. Unless there’s an alternator to charge it, a standard battery cannot power a car to a start. Without an alternator, a car battery can only last about 20 to 30 minutes or less. The longevity depends on the driving terrain and the amount of workload on the battery. 

  • Keeps Car and battery Running

The electrical system in a vehicle starts with the battery powering the car into starting. The alternator helps to keep both the car and battery running all through your trip.

The battery doesn’t power the electricity chain in your vehicle. It only begins the process by powering the starter motor. As the car drives, the alternator generates the electrical momentum that sustains the moving vehicle’s electrical chain while charging the vehicle’s battery. 

  • Powers car Electrical System

The alternator is responsible for powering most of the car’s electrical components. While some electric current may come from the car’s battery, much of the electricity that the car uses comes from the alternator. 

The alternator powers car parts, such as ignition coils, wipers, fuel injectors, engine cooling fans, radio, and more. 

  • Converts One Form of Energy to Another

The alternator is responsible for converting mechanical energy to electrical energy. During combustion in the chambers, gas comes into the crankshaft-bound engine pistons from the fuel tank. The crankshaft, therefore, converts the energy to the car’s serpentine belt, which connects to the alternator. 

The spinning of the alternator pulley generates electric power which converts mechanical energy to electric energy. The alternator achieves this energy conversion by supplying power into the copper cable and magnet. 

How Does A Car Alternator Work?

As we already mentioned, the alternator has four components that play key roles in its functions.

After the battery has initially powered on the vehicle, the V-belt causes the alternator’s pulley to twirl by turning the rotor at great speed. The rotor is in the stator, which is a group of magnets. Thus, electromagnetism generates the electricity, and copper wires transmit the electricity to the diodes, which convert the A.C to D.C. In this D.C form, the battery utilizes the power.

The voltage regulator allows sufficient voltage to the battery and blocks the supply if it is too much. The regulator opens up the supply to the battery again when the battery has gone down.

How Long Does A Car Alternator Work?

Essentially, the alternator works a lot more than the battery in the sense that you can disconnect the battery after starting a car but the alternator has to keep charging the battery. 

Typically, a car alternator can last up to seven years. This is equivalent to between 100,000 and 150,000 miles. And depending on the make and condition of use, an alternator can last for less than the set mileage or have a shortened lifespan. Some can only work for just 80,000 miles.

How To Diagnose & Replace A Bad Alternator?

Some signs will indicate that your car alternator is going bad. If you observe any of these signs discussed below, it could be that your vehicle needs a new alternator.

  • Slowing down of Electrical Components: When you notice that the dashboard is dim, the windshield wipers are slowing down, the radio is cutting in and out, these are all indications that the alternator is having issues generating or sustaining power.
  • Battery Light comes on: You’ll notice this light on the dashboard as a battery shaped icon with ALT or GEN written on it. 
  • Weak Battery: The alternator ought to convey energy to the battery, but there is nothing the alternator can do if the battery is weak or dead. 
  • Foul Burn Smell: A burning may have produced this smell in the alternator’s belt. The burning is because the belts are not turning. 
  • A Grinding Noise: if something goes wrong with any of the alternator’s internal components, there’s a disruption of the rotation which leads to the grinding noise.

How To Fix a Bad Alternator?

To replace an alternator, you could buy an aftermarket alternator or an Original Manufacturer’s Equipment (OEM). The aftermarket alternators represent rebuilt alternators that were once bad. These alternators wouldn’t cost as much as those produced by the original manufacturers.

Another way to get a new alternator is to have your damaged alternator worked on. Ensure the mechanic only replaces the bad components as services the alternator.

Final Thoughts

Alternators are very important components of a vehicle. And as much as possible, they should be cared for to keep them performing at optimized levels. Usually, an alternator will go bad, not function well, or have a short lifespan if there’s no protective engine undercover or has developed a fault.

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