Your Vehicle’s Battery System


As the engine provides only mechanical energy, it does not generate electricity. So, we need a power source which produces electricity to power all the electrical accessories in your car. 

Your vehicle’s battery and electrical system might be one of the most complicated systems in your vehicle. Its main purpose is to provide an electric current to the electric-powered starting motor, which in turn starts the chemically-powered internal combustion engine that actually propels the vehicle. The car battery provides a spark of electricity necessary to provide power to all the electrical components in your vehicle. Some batteries can last up to 5 years.

How does the charging system work?

The vehicle’s charging system consists of a car battery, the voltage regulator, the alternator, and fan belt.

The fan belt is a flexible rubber belt that puts together certain engine components. The rotating motion of the fan belt, causes the alternator pulley to turn. The movement of the alternator pulley generates power, which is the delivered to the alternator. Your alternator converts mechanical energy to electrical energy with an alternating current.

Chemical energy is being converted to electrical energy in the battery. This electrical energy is then delivering voltage to the starter, in order for the car to start. The battery is also stabilizing the voltage in order to keep your engine running. The voltage regulator sends the power from the alternator to the battery, controls the amount of energy to provide a steady flow of power to the battery. 

If your vehicle won’t start, it’s usually caused by a dying or dead battery, loose or corroded connection cables, a bad alternator or an issue with the starter. It can be hard to determine if you’re dealing with a battery or an alternator problem.

The alternator plays a very important role in the battery system. Like mentioned, its main responsibility is to convert chemical energy to electrical energy so that you can charge and replenish the battery in your engine and other electrical components in a car.” Most of them last between 7 to 10 years in optimum conditions.

However, there are several ways to tell if your alternator or battery is exhausted. These signs include:

  • Dim Headlights
    A weak battery will not provide the required power to the electrical components, which will cause your headlights to be dim and not shine as bright as they need to. The alternator pulley allows the V-shape or serpentine belt to spin the alternator and is driven by the engine’s accessory drive system. 
  • Clicking Noise/Slow Start
    Your vehicle should start as you turn the key. Any delays during this process, such as clicking noises or the engine simply not turning over may indicate a faulty battery.
  • Battery Is Corroded
    Battery acid can often leak out of the connection points, causing a build-up on the battery. Wiping away the corrosion at the connection points may work for a short time, however, this will cause your battery to not function at its optimal voltage.
  • Car Doesn’t Start

         Cars are designed to start by simply engaging the ignition. While several tries to start your car with eventual success may imply an                  issue with the starter, the inability to start may be your vehicle’s way of indicating the need for a battery change.

  • Backfiring Engine
    A battery at the end of its life may create sparks, which would cause fuel to collect in engine cylinders. The ignition of this fuel can cause a reaction called a backfire.
  • Battery Warning Light Comes On

         If your battery warning light comes on while you’re driving, it means that your battery is no longer being charged and is running only           on its own charge. The battery will eventually run out of power that will cause the vehicle to come to a stop.

At VAG Spec Centre, we specialize in batteries. Make sure that you visit us if you experience any of these symptoms.

We have branches in:

Randburg: VagSpec Centre Randburg – Out of warranty Vw, Audi and Seat auto service shop (

Menlyn: VAG Spec Menlyn – Out of warranty Vw, Mercedes, Audi, BMW and SEAT specialists

Zeerust: VAG Spec Centre Zeerust – Out of warranty Vw, Audi and Seat auto service shop (

Klerksdorp: Vagspec Klerksdorp – VW & Audi Specialists In Klerksdorp

Capetown: VAG Spec Centre Cape Town – Out of warranty Vw, Audi and Seat auto service shop (

George: (opening 1 September 2022) VAGspec Garden Route – Volkswagen, Audi, SEAT & Porche Specialist Repair Centre (

Contact Us:

Menlyn Contact form