Signs You May Need a New Battery

July 28th, 2023 by

You probably don’t give your car’s battery much thought. After all, it sits in the corner of the engine compartment under the hood, quietly providing the energy to start and operate your vehicle. You only notice it when the engine labors to start or fails to turn over.

This lack of attention can come from not fully understanding the battery’s pivotal role in operating your car. At Classic Toyota in Tyler, Texas, we understand the battery’s importance. That’s why we test your vehicle’s battery at every service visit. Continue reading to learn more about your car’s battery and how to know when you need a new one.

The Automotive Battery Explained

Your car’s battery provides the spark to start the engine. It then keeps the motor running with some help from the alternator. So when the battery fails, your car won’t start, and there’s never a good time for this.

The battery system is a simple yet complicated energy transformation process. The battery stores chemical energy, which converts to electrical energy when you start the ignition system by turning a key or pushing a button. This electrical energy travels to the engine starter, which sends it to the spark plugs to ignite the fuel in the engine’s cylinders.

At this point, the engine provides mechanical energy to propel your car. The electrical system continues to work, giving all your vehicle’s electrical systems power. But the battery needs help from the alternator. Otherwise, it would eventually run out of chemical energy and die, precisely like the batteries in a flashlight.

The alternator in your car turns mechanical energy into electrical energy through a belt and pulley system the engine powers. This clever part provides additional electrical energy distributed to your car’s electrical system and returns electrical energy to the battery stored as chemical energy for later use.

Why Batteries Fail

Almost half of all car breakdowns are because of battery failure. But that doesn’t always mean you need a new battery. Many replace it only to have the new one die in a few days. There are other reasons batteries fail. Understanding these reasons will help you know when to replace the battery or repair something else.

Your Daily Commute

How you drive can lead to battery failure, but it isn’t about how fast or slow you go. Instead, the distance you drive affects the battery’s health. The natural byproduct of the battery’s chemical conversion process is sulfation. Sulfation occurs more when you drive shorter distances. Longer commutes produce less sulfation and a stronger recharge.


Extreme temperatures can affect the battery’s health. Hot temperatures have less impact than cold temperatures. Scientific studies show that car batteries weaken by 30% when the temperature reaches 32 degrees Fahrenheit, or the freezing point. When the thermometer hits zero degrees, the battery depletes by 60%. So it has a much higher chance of failure in cold weather, especially if it’s already compromised.

Alternator Failure

Think of the alternator as a generator that produces electricity and sends it to the different electrical systems and the battery for storage. If your car’s alternator fails, it stops sending energy to the battery for storage. The engine and electrical systems continue to run but draw electricity from the battery. Soon, the battery runs out of energy, and the car stops running.

Most alternators will last 10 years or longer and don’t require any maintenance. But they wear out eventually, so testing the alternator when the battery fails is essential. In most cases, you can replace the alternator without replacing the battery.

Leaving the Lights On

Human error often leads to battery failure. If you’ve left the headlights or interior lights on overnight, you’ve probably experienced battery failure. Because the engine wasn’t running, the alternator wasn’t returning power to the battery. The lights drained the battery’s energy until there wasn’t any left.

If this happens, you can jump-start your car. Once the engine starts running, the alternator returns power to the battery, eventually recharging it. We recommend keeping a set of jumper cables or a portable jump kit in your car, just in case.

Signs of Imminent Battery Failure

Symptoms of battery failure can be obvious or subtle, depending on the cause. Here’s a list of common signs of battery failure and the recommended course of action:

Straining Engine at Startup

If the engine labors to start, it isn’t getting the necessary electrical energy. You’ll also notice the heater, radio, and lights won’t work when starting the engine. If the battery is the issue, these ancillary systems will operate normally once the engine starts. If they don’t, you probably need a new alternator.

Engine Doesn’t Turn Over

A failing battery will cause the engine to strain at startup until the battery runs out of power. At this point, the battery is dead, and you’ll need to replace it. Unfortunately, depending on your driving habits and the weather, your car’s battery lasts only two to five years.

Corrosion and Sulfation

Batteries have metal plates and acid inside. Acid naturally corrodes the metal, creating sulfation. Over time, the corrosion leads to failure. You’ll see what looks like blue, green, or white algae blooming around the battery’s terminals when corrosion and sulfation occur. We recommend using a wire brush to remove the algae, allowing for stronger recharges.

Test Your Car’s Battery in Tyler Today

If your vehicle shows the signs above, bring it to our service center so our Classic Toyota team can test the battery and electrical system. Our technicians will provide a detailed explanation of the problem and a written estimate to fix it. Most batteries have a warranty that covers failure for up to five years. And we have an expansive battery inventory to fit all Toyota models at competitive prices. We recommend scheduling battery service online. But you can also drop by our service center. We can usually test and replace your car’s battery in under 30 minutes.


2007 11 22 – N Attleboro – Battery by thisisbossi is licensed with CC BY-SA 2.0

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