A vehicle is ignited and started by an electrical system. The automotive electrical system is analogous to our body’s circulatory system, where the battery is the heart from which the electricity (blood) flows. Like blood, electrical current flows from the battery to the powered part and back through the car’s metal body.
The battery serves as the electrical system’s backbone. It gives the car the electricity it needs to start and powers other parts, like the fuel and ignition systems, which are needed for the engine to work.
Hence, this blog is to elaborate on the automotive electrical system, its components, and its functioning.
Main components of an automotive electrical system
There are three main components of an electrical system.
- Battery
Your vehicle’s entire electrical current is supplied by its battery until it is started. This includes the current to the ignition and fuel systems, which are responsible for producing the combustion necessary for your engine to operate.
- Starter
While the battery provides the power to start a vehicle, it is the starter that actually starts the engine. The battery supplies the starter motor with a small amount of power. The starter then rotates the flywheel, which rotates the crankshaft and initiates piston movement. Due to the complexity of this procedure, it is essential that the starter work.
- Alternator
The alternator keeps the battery charged and the electrical system operational while the engine is running. With a faulty alternator, your vehicle may start, but it will not be able to run for an extended period of time. If the alternator needs replacement, the electrical system of your vehicle will operate erratically, the battery will deplete, and the engine will eventually lose power.
How does the current flow within a vehicle?
Current flows out of the battery via its positive terminal and back in via its negative terminal, also known as its “earth terminal,” because it is connected to the car’s chassis and therefore cannot electrocute you. This configuration is known as an earth-return system.
Electricity flows along wires of various hues (and resistance) that are bundled and run the length of the vehicle. This is known as a writing loom.
It is extremely complex and has wires running off it at intervals to connect to power-requiring components.
Types of Batteries
Starting batteries: These batteries start your car. They deliver a short, powerful burst of energy to start the engine. They stay charged during regular use because the alternator recharges them when it starts charging the electrical system.
Deep-cycle batteries: These batteries provide less energy over time. While they can start a car, they are designed to run fridges, winches, and other electrical components that draw a smaller but regular current. Within these categories, lead-acid batteries differ in their materials.
Wet Cell: This is the most common type of car battery and may be maintenance-free or require periodic watering.
Absorbed Glass Mat: Like wet cell batteries, but with a glass mat between each lead plate. This electrolyte-soaked mat reduces battery slosh. It lasts longer than a wet-cell battery.
Gel Cell: As the name suggests, this battery uses a gel electrolyte. They’re smaller than wet-cell batteries.
The working principle in automotive electrical systems
Car electrical systems are easy to understand. All electrical devices in a car are powered by the battery through switches or relays. The engine immediately starts the battery-powered starter motor. The alternator charges the battery while the engine burns fuel.
When the engine is off, this alternator’s voltage is lower than the battery’s. The battery, not the alternator, powers the vehicle’s loads. Diodes prevent current from entering alternators.
The alternator’s current output exceeds the battery voltage when the engine is running. The alternator charges the vehicle’s battery and electrical load. When the engine is running, an alternator’s output voltage is above the battery voltage.
Wrapping Up
The electrical system is a complex but essential component of your vehicle’s ability to start, run, charge, and perform small but essential tasks such as locking the doors. Moreover, despite the fact that the voltage in automotive systems is significantly lower than in, say, household applications, it is essential to seek the assistance of a professional when making a diagnosis or beginning repairs, as many components are extremely sensitive and can be easily damaged without the proper training and knowledge.
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