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Car Care Advice

10 Prominent Weak Car Battery Symptoms: How To Recognize Them + 5 FAQs

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Do you suspect your car battery is failing?
Can your car run on a failing battery?

In this article, we’ll cover the most common weak car battery symptoms and some FAQs about car batteries.

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 Let’s jump in.

10 Prominent Weak Car Battery Symptoms

If your car is plagued with a failing battery, here are some common signs you’ll likely experience:

1. Dim Headlights

Headlights are an electrical component powered directly by the battery. If your headlights are dimming, they’re not getting enough battery power. While dim headlights can also be a sign of another electrical problem, like a bad alternator — you should get your battery checked. 

Not only are dim headlights a safety concern, but they could also be one of the symptoms of a dying battery. 

2. Slow Engine Crank

One of the first telltale signs of failing battery power is a slow, long crank before the engine starts. If you notice a difference in your normal startup of the car, you can get your battery checked. In most cases, you’ll only need to recharge your battery. 

3. Clicking Noise When Trying to Start The Car

If you hear a clicking noise when you turn the key in the ignition, it indicates a low-power battery issue — or even a dead car battery. A dead battery can also be the result of a faulty alternator. 

Either way, you’ll probably have to jumpstart the vehicle and pay a visit to your mechanic to decide whether to go for a car battery replacement.

TIP: Ensure you keep a set of jumper cables stashed in your boot for this situation.

4. Gas Pedal Needs to Be Pressed to Start The Car

A typical vehicle doesn’t need gas to start. If you have to push down on the accelerator just to get your vehicle started, you probably have a bad battery and should let an auto repair technician decide whether you need a new car battery.

5. The Engine Backfires

In rare cases, a failing battery can produce sparks that cause your engine to backfire. 

This is a symptom you won’t miss, but an engine backfire can result from many underlying problems — not just a battery issue. 

It’s best to let your mechanic check all causes (including the possibility of a bad battery) if you notice backfiring. 

6. Smell Of Sulfur

A swollen or aging battery can leak its internal battery acid — and by doing so, emits a strong smell of sulfur. If you notice a sulfuric smell around your vehicle, immediately check on your battery and replace it. 

A bad battery will die eventually, but the battery acid that leaks out can corrode parts of your engine — leaving you with an engine repair bill that’s much higher than replacing a bad car battery. 

7. Swollen Battery Case

If you notice a bulging or warped battery, it’s likely due to a buildup of hydrogen gas inside the battery case — and you’ll need a new car battery. 

This can happen because the battery life is over, the battery is subject to extreme temperatures, or when a bad alternator overcharges the battery. An alternator can overcharge the battery due to issues with the voltage regulator.

In any case, a swollen battery case means you’ll need a car battery replacement. 

8. Corrosion Of The Battery Terminals

Corrosion around the positive terminal or negative terminal is a sign of an overcharged or leaking battery — which significantly weakens battery power. 

If you see a battery terminal covered in a bluish crystalline substance, battery acid has leaked out, causing corrosion at the battery terminal — and it’s time to get your vehicle a new battery. 

9. Low Battery Fluid

Some batteries have removable caps so owners can check battery water (electrolyte) levels. 

If you often have to top off the fluid or the battery warning light comes on, it’s an indicator of a bad car battery. 

This happens when cell plates accumulate sulfur and causes the electrolyte to turn into oxygen or hydrogen gas, which leaks out of the battery terminal. 

10. Jumpstarts Are More Frequent

If you need to plug in your jumper cables to a neighbor’s car and jumpstart your vehicle regularly, the battery power is low, and it probably can’t hold a charge anymore. 

Decreased capacity is a common feature of an old battery. You’ll need a mechanic to check if a new battery is required. Alternatively, you could have a failing alternator that can’t charge the battery. 

Now that you know the most common symptoms of a weak or dying car battery — let’s jump into some FAQs.

FAQs About Weak Car Battery Symptoms

Here are answers to some common questions about weak car batteries:

1. Can Cold Weather Deteriorate My Car Battery?

Cold weather causes battery potency to decrease dramatically. Even a new battery loses about 35% of its power at below-freezing temperatures. 

At about 0oF, car batteries can lose up to 60% of their potency, while your alternator and starter motor can also be damaged.

At these freezing temperatures, vehicles need almost twice as much energy to start. This makes your battery work harder and wear out quickly, causing it to weaken until it eventually dies. 

2. How Can I Tell If My Car Battery Needs To Be Replaced?

You might want your battery to last as long as possible to get the best value for your money. However, keeping your battery’s health in mind is important so you won’t end up with a dead battery. 

If you experience the bad car battery symptoms we’ve mentioned above, or if your battery warning light (dashboard light) turns on, measure your car battery voltage with a multimeter. Your check engine light might pop on too. 

As a rule of thumb, if a fully charged battery has a voltage below 10V, you’ll have to go for a battery replacement. 

3. How Does A Weak Battery Affect My Car?

Your battery plays a big part in powering your car’s electrical system — including every electrical component, like the windshield wiper and power windows.

A weak battery can affect almost any electrical component in your car, including the charging system. It’ll result in dimmer headlights and trouble when starting up the vehicle. 

Weak batteries can also affect your starter motor and alternator. When the power from the battery is low, the starter motor and alternator will draw excessive voltage to compensate. 

This can eventually result in a bad alternator and a bad starter motor.

4. Can My Car Run With A Weak Battery?

Yes, your vehicle can run on a weak battery for some time, but you shouldn’t let it happen.

A weak battery will continue to worsen until it dies, and you might be left stranded on the road with a dead battery and another electrical problem like a failing alternator. 

As soon as you notice weak car battery symptoms, get an auto repair technician to check your vehicle. Otherwise, you might end up paying a lot more than the cost of a new car battery.

5. What’s The Best Way To Deal With A Weak Car Battery?

Realizing your car battery is dying can make you think about all the problems that come with it, but you don’t have to worry too much. 

Contacting a qualified mechanic can help you sort out almost any weak battery issue. 

Luckily, you can just call a mobile mechanic — like RepairSmith!

What’s RepairSmith?
RepairSmith is a mobile vehicle maintenance and repair service designed for your convenience.

You can fill out this form to get an accurate battery repair and service estimate.

Wrapping Up

Your car battery is a critical component of your electrical system. 

Most vehicle batteries come with warranties for several years. However, it’s essential to occasionally test your battery and other charging system components. This helps prevent getting stranded with a dead car battery.

If you realize that your battery needs repair, you can trust RepairSmith to get the job done. Get in touch with us, and our expert technicians will drop by to help you out!