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What does a car battery do?

You might have heard your vehicle needs a new battery, that your battery is old or struggling in cold weather, but what does the battery in your car do? What’s it for?

What is a battery?

Before explaining what your car battery does, a quick refresher on what a battery is.

Batteries are simply a group of one or more electrochemical cells that can hold energy and release it in the form of an electrical current. So what does a car do with this current?

The purpose of a car battery

Modern vehicles have quite complex electrical systems, which the battery is tasked with providing power for. Things like your stereo, headlights, driver assist systems and more all require electrical energy to function.

For vehicles with petrol or diesel engines, the starter motor requires huge amounts of energy to crank the engine over before it will run on its own.

While starting the engine, the battery also provides power to the engine management computer. It’s essential that this is powered at the same time as the engine is cranking, so that the computer can time for, and adjust, spark and fuel delivery.

When the engine is running, an alternator will provide current to ensure the battery is kept at an appropriate voltage to run all the electronics and ensure the battery has enough power to restart the engine once you stop your car.

Alternators also function as a voltage regulator, they absorb spikes in your alternator output as well as supply extra current in the event that your vehicle draws more than your alternator is supplying. Minor voltage fluctuations are normal in a functioning vehicle.

Battery or charging system indicator light

How long does a battery last?

Most batteries used in vehicles typically have a useful lifespan of between 3 and 5 years.

Depending on your local climate (cold or warm), the type of vehicle, and your driving habits the lifespan can be longer or shorter. For example, if you only take short, 5-minute trips, your battery won’t last as long as someone who routinely drives for longer periods of time. This is because the alternator hasn’t had enough time to fully recharge the battery.

It’s possible to find 10 year old vehicles with their original battery, while it’s not unheard of for vehicles to blow through multiple batteries in 12 months a piece through no fault of the battery.

There are multiple signs that your battery is faulty and needs replacement that you can check for, without the need for specialist tools and diagnostic equipment.

How much should a car battery cost?

The price of a new car battery varies greatly and depends on a few factors:

  • The size of the engine
  • The physical size of the battery
  • The energy rating requirement of your battery
  • Whether the vehicle has start-stop technology
  • Whether your vehicle is stock or is modified (extra accessories require more power)

As such it’s not easy to give a one-size-fits all quote, but reach out today and tell us what vehicle you have and we’ll give you a price in just a few minutes.

See the expert team at your local Tyrepower

It’s a great time to check your battery a few days before a long trip, or whenever you have your tyres checked or rotated.

If you experience difficulties starting your vehicle, a battery check is a quick and easy check that can be done.

Come and see your locally owned and operated Tyrepower store today!

Request a quote and we will be in touch via SMS shortly

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