Under-the-Hood Basics: Get to Know Your Car Battery

  • Jan 24, 2022
image of mechanic working on battery image of mechanic working on battery

When you think about what makes your car run, the engine is probably the first thing that comes to mind. But your vehicle’s battery is just as crucial to the operation of your vehicle! Get to know the powerhouse that is your car battery by understanding why it’s important, how it works, and signs it’s time for a new battery

Why Your Car Battery Is Important

Your vehicle’s battery provides the necessary power to start your vehicle. It converts chemical energy into electrical energy and delivers that energy to the starter to allow your engine to turn over. Without the battery, your starter wouldn’t get the jolt of energy it needs to start the engine, and your car wouldn’t be going anywhere anytime soon.

How Does a Car Battery Function?

A battery’s overall function is simple in theory. But the actual process of how your battery creates electrical energy is pretty scientific. Most vehicles use what’s called a lead acid battery — lead plates are submerged in an acid solution, producing a chemical reaction that releases energy. This chemical energy is stored in the battery until your vehicle needs it. It is then converted into the electrical energy needed to power your car. 

Unlike a typical household alkaline battery, a lead acid car battery is rechargeable. Your vehicle’s alternator sends electrical energy back to the battery, which is then converted back into chemical energy. This process is what recharges the battery. 

How Does the Battery Work in a Car?

The battery sends electricity to the starter motor — a small motor positioned near the engine. Once the start motor receives power from the battery, it engages a small gear that then connects to a larger gear on the engine called a flywheel or flexplate. The starter motor turns the flywheel which turns the crankshaft and starts the engine’s combustion process. Once the combustion process has started, the starter motor disengages, and it and the battery’s jobs are complete.

Can Your Car Run Without a Battery?

Technically, your car could run without a battery in some cases. The alternator, which is driven by the engine’s serpentine belt, supplies the electricity your vehicle needs during operation and recharges your battery. Without a battery, however, your vehicle wouldn’t have a power source to start the engine and subsequently power the onboard electronics.

Your battery also has the job of providing backup power. If your vehicle is using more electricity than the alternator can produce, your car will use electricity from the battery to make up the difference. If your vehicle is pulling backup power from the battery too often or for too long, you risk draining the battery since the alternator won’t be able to keep up with recharging the battery. 

Fortunately, the alternator is designed to provide the power needed to run all the factory-installed electrical components in your vehicle, including aftermarket accessories like external lights, trailers with powered lights, 12V car accessories, etc. If you’re using a lot of accessories and your battery keeps dying, stop by one of our many Tires Plus locations to have your vehicle's charging system checked. We can also test for parasitic draw. 

Signs It’s Time to Replace Your Car Battery

Extra accessories can drain a battery, but a healthy battery can be recharged by the alternator after a quick jumpstart. An old or dying battery, however, may not. You may need to replace your car battery if you notice things like:

  • Your vehicle is slow to start. You may hear a sluggish cranking sound when trying to start the car.
  • The battery case is swollen or bloated.
  • You hear rapid clicking noises and the vehicle does not crank.
  • It smells sulfuric or like rotten eggs.
  • The battery is leaking or cracked.
  • Your battery is three or more years old.
  • Some vehicles may illuminate a check engine light for low battery voltage. 

Get Expert Battery Replacement from Tires Plus

If you’re waiting on bad battery symptoms to notify you of a worn-out battery, you’re likely waiting too long! Stay ahead of battery problems by getting your battery tested for free at your nearest Tires Plus. If it’s time for a new one, a professional Tires Plus technician can install a new DieHard battery that’s right for your vehicle to ensure it gets the power it needs. Schedule an appointment online or head to your local Tires Plus for expert battery services.

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