name of parts of charging system in a vehicle

understanding charging system in automobile engine

Both vehicle users and mechanics need to have a basic understanding of automobile charging systems. The charging system powers the electrical components of a vehicle. in modern engines, it consists of the alternator, battery, wiring, and electronic control unit (ECU). Older designs use regulators, but since newer cars are computerized regulators are often found in the alternator.

name of parts of charging system in a vehicle

The above-mentioned components play a very important role in the automobile charging system which is why they must work hand in hand to accomplish their purpose. Today, you’ll get to know the definition, functions, parts, diagram, working, common problems, and advantages and disadvantages of the charging system used in automotive engines. So,


What is a charging System?

The automobile charging system is a set of components working to keep a charge and provide electrical energy for the vehicle’s electrical devices. Modern vehicles are now designed with many electrical parts which makes them require a large amount of electrical energy. The charging system powers the headlights, dashboard indicators light or warning lamps, fuses, relays, engine plugs, brainbox, ECU, radio, control screen, fuel injector system, sensors, etc. All these components are interconnected to the car battery which is charged by the alternator.

Functions of Charging System

Below are the functions of the charging system in automobile engines:

  • The primary purpose of the charging system is to provide power to all electrical components in a vehicle.
  • It comprises an alternator that maintains and keeps the vehicle’s battery charged.
  • The charging system supplies electrical current to fire the spark plugs, which ignite the air/fuel mixture in the combustion chamber,
  • Alternators help to charge dead batteries, while the engine is running.
  • The charging system help to send the engine’s mechanical issue to the engine’s ECU using a sensing device.
  • Vehicles’ electrical components are powered when the engine is not running.

More functions will be covered as we explain the components of the charging system.

Components of Engine Charging System

Below are the major parts of the charging system in automobile engines:


An alternator is one of the major and inevitable parts of an automobile charging system as it plays the best role. The electrical power that charges the battery is from the alternator, but the current produced is alternating current (AC). This AC power is immediately converted to direct current (DC) because automobiles use a 12-volt DC electrical system. A dead battery does not mean there is something wrong with it. it is just that being deprived of charge, this is why the alternator is also checked if a car is not starting.

Voltage Regulator:

The voltage regulator controls the alternator’s power output. Though this device is often located in the alternator, as it regulates the charging voltage that the alternator produces. It keeps the voltage between 13.5 and 14.5 volts to protect the electrical parts in the vehicle. in modern vehicles that use ECU to sense when the battery needs to be charged as controls the volt supplied. The warning lamp in the dashboard indicates something is wrong with the charging system. Often time the warning lamp is indicating a faulty alternator, resulting in an uncharged battery.


The battery is another essential of the automobile charging system, as it serves as a reservoir of electrical power. the engine’s starter motor is directly connected to the positive terminal. It helps to crank the component making the engine start. As the engine is running, the alternator directly charges the battery. The battery can also supply power to the electrical components when the engine isn’t running.

Charging system diagram:

diagram layout of an automotive charging system

charging system components

Working Principle

The working of a car charging system can be complex or easy, depending on the design. Well, the diagram layout of a vehicle charging system has been indicated below in this post. It shows the alternator, battery, and vehicle loads, which are the electric components. in its design, the alternator voltage is less than the battery voltage when the engine is not running. This is because the current from the battery is used to power the vehicle loads and not the alternator. The alternator contains diodes that prevent current from flowing into the alternator.

In a situation where the engine is running, the alternator current output is greater than the battery voltage. The current flow from the alternator to the electrical load in the vehicle and the battery to charge it up. Conventionally, the alternator’s output voltage is above the battery voltage when the engine is working.

Now you can see the vehicle’s electrical load is still powered even though the engine is not running, as far as the battery is charged enough. Though a large amount of energy is needed to power the various electrical system contained in a vehicle. Batteries can still meet reasonable electrical demands depending on their strength.

A car charging system begins working when the starter key is in the ignition, at the point the vehicle’s electrical components rely on the battery. As soon as the engine begins working alternator starts supplying power to the components and battery. This is why the battery is charged when the engine is running.

Working charging system in the video:

Symptoms of Bad and Failing Charging System

As time goes on you can experience failure in your charging which can be often time caused by its components. below are the symptoms of bad charging in an automobile engine:

Bad Alternator

If the alternator goes bad, the complete charging system won’t work as well. Most time, the voltage regulator is always affected inside the alternator, since it controls the amount of current that flows to the car’s electrical part. Alternators can offer higher voltage output if the regulator fails which can cause a problem to the car battery and components that rely on it. This is because the alternator has no power over the car’s 12-volt system.

On the other hand, a bad voltage regulator can send low voltage output to the car battery and electrical components. with this, the battery is prevented from charging fully and the parts won’t be properly powered. if care is not taken when the alternator goes wrong, the car’s electrical system will be powered by the battery and drain off.

Worn or Broken Belt:

A broken alternator belt causes the system not to work well and the worn belt will often slip. This will cause the voltage regulator to send a low charge to the battery and the electrical system since the alternator is not spinning fast enough.

This issue is sometimes hard to detect especially when it happens when the car is on a drive. But consider changing the belt as soon as you notice.

Bad Battery:

A bad battery is another big cause of a bad and failing battery, a few years of the used battery will stop holding charge. Automobile batteries can normally last two to five years, so you can try remembering how long you’ve used them.

Well, you can get the battery tested which is done for free in some automobile workshops, if it works fine then you can consider checking the connection between the alternator and the battery. corrosion on the terminals can reduce the conductivity, so consider crabbing off.

In conclusion, a charging system is a great setup that aids all electrical components in the car. It is the reason we can charge our phone or light cigarette in a car. This article has introduced you to its definition, and parts which have been further explained in another post, you’re expected to check them out. We’ve also seen how automobile charging system works and some bad symptoms that occur.

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I hope you enjoyed the reading, if so, kindly comment, share, and recommend this site to other auto students. Thanks!


4 responses to “understanding charging system in automobile engine”

  1. Great article on the charging system! I found it very informative and helpful in understanding the different parts and functions of a vehicle’s charging system. As a beginner in this field, I appreciate the clear explanations and diagrams provided. Keep up the good work!

  2. Very informative post! I had no idea the charging system in a car was so complex. The breakdown of the different functions and parts was really helpful in understanding how it works. Thank you for sharing!

  3. Great post! I found the explanation of the charging system in vehicles to be very informative. The breakdown of the different parts and functions was helpful in understanding how the system works together to provide power to the vehicle. I especially appreciated the examples of how a faulty charging system can lead to serious problems. Thank you for sharing this valuable information!

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