How Do You Tell If It’s Your Battery Or Alternator?

Are you finding it impossible to start your car? At times, cars fail to start even after turning the ignition switch. If you ever experience such a problem, you need not worry.

More often than not, if the car does not start, there could be a problem with the battery or alternator. So, how do we identify the exact cause of the problem?

Battery or alternator: How can I tell the origin of the problem?

When you start the car, the battery delivers electricity to the starter. Then, the engine begins running, and the alternator starts functioning.

Once the alternator is in action, it charges the battery. And the car turns on. If your finding trouble starting your vehicle, consider jump-starting it first.

If the battery is the problem, jump-starting will help you turn on the car. Conversely, if the engine goes on and then goes off after jump-starting, your alternator could be the problem.

On the flip side, if the vehicle goes on after a jump start but can’t start again using its own power, you could be having a dead battery.

Signs of a dead battery

Below are some of the signs that can help you identify if you have a dead battery.

Dim dashboard lights:

One of the most common signs of a failed battery is dim dashboard lights. Usually, your battery is responsible for running several components in your car’s electrical system.

If the battery is not working effectively, it affects these components. As a result, dashboard lights won’t be as bright as usual if you have a bad car battery.

Even so, there are other causes of dim headlights.

Battery corrosion:

After some years of use, your battery can experience corrosion, especially on the positive terminal. So, if your car is not starting, check the battery for any signs of corrosion.

If you notice corrosion, wipe the battery using a clean, dry cloth. Battery corrosion often appears like a blue film on the positive terminal.

After wiping the battery, jump-start the car. If this solution still does not work, your alternator could be the problem.

An old car battery:

Most car batteries have a lifespan of two to three years. After years of use, they wear out and deliver low efficiency.

In fact, the battery charge continues to diminish to the point it doesn’t have enough energy to start the engine.

Luckily, you can incorporate a wide range of techniques if you wish to extend the battery’s durability.

Signs of a bad alternator

There are several things that can help you identify a problem with your alternator. Some of them include:

Dim interior lights

Car experts often recommend monitoring the interior lights of your car. If you notice that you have dim interior lights, check the alternator.

The alternator could be having a problem delivering insufficient energy to the battery.

Dim or overly bright headlights

Another common sign of a bad alternator is overly bright headlights. If your headlights become too bright when you press the accelerator, examine the accelerator.

Also, if your headlights are dim, you could be having a bad alternator. A bad alternator does not charge the battery a required. And this is why you are likely to experience dim headlights and interior lights.

Growling noises:

Pay attention to noises coming from your car. At times, you may hear a growling sound coming from the vehicle just before the alternator breaks down.

When this happens, it would be best to replace your alternator. This is the safest way to save the problem.

The smell of burning rubber or hot wire:

Have you ever heard the smell of hot wire or burning rubber? This often indicates a bad alternator. So, get your alternator checked and replaced.

Test the alternator

You can avoid having a bad alternator by checking it from time to time. Get a car professional to check the alternator and fix any existing problems.

Note that repairing an alternator is relatively costly. So, ensure you find the right person for the job. Otherwise, you may end up losing thousands of dollars.

How do you keep your car battery in good condition?

Car owners can extend the longevity of their car batteries by incorporating specific techniques. Generally, a car battery can last for about three years.

But durability varies depending on how well you maintain the battery. Below are a few ways that can help you prolong the longevity of your battery.

Limit Short Rides:

Avoid going for short rides; you would instead go for long drives. A short car drive does not give the car enough time to charge. And this can drain the car battery.

Additionally, do not let your car sit for an extended period without starting it. If you rarely drive your car, it would be best to have a portable battery charger.

One of the main advantages of having a portable car charger is that you can jump-start without another car.

Tighten and secure your battery:

Always make sure your battery remains fastened. A battery that is not secured can cause internal damage to the car.

If you often drive on bumpy roads, check the battery to ensure it’s in a good position. Also, get the battery terminal evaluated frequently.

Switch off the lights when the car is not in use:

 Your headlights and dashboard lights use energy from the car battery. So, avoid turning them on, especially when they’re not in use.

Failure to do so would drain the battery. Consider placing a sticky note to serve as a reminder of when you should turn off the lights. Also, avoid turning on your car lights on a bright sunny day.

Control the Corrosion:

Did you know that you can prevent car battery corrosion? One of the ways you can do this is by keeping your battery clean at all times.

Use a clean toothbrush and baking soda solution to scrub the car battery gently. Focus on cleaning the positive terminal since it is more vulnerable to corrosion.

Then, use clean cold water to rinse the mixture and dry it using a clean cloth.


You can tell your alternator has a problem if the car won’t start after jump starting. On the other hand, you can tell you have a bad car battery of the vehicle starts after jump starting.

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