9 Warning Signs That Your Car’s Battery Needs Replacing

Your car battery is a crucial part of your vehicle. It provides power to your starter, which fires up your engine, and it also provides power for all electrical components in your car. But how do you know if your battery needs replacing? At Finsanto Automotive, we are experts in car battery service.

Here are 9 common warning signs:

1. Your car won’t star

t The most common indicator of a battery going bad is when the car won’t start. You turn the key, and nothing happens, or the dash lights come on, but the engine doesn’t turn over. Multiple problems could be responsible for this symptom, including a bad ignition switch, faulty starter, broken cable, or blown fuse. A weak battery would be near the top of the list, though.

2. The engine is slow to turn over

If your car starts eventually, but it takes a long time to crank up, that’s another sign the battery is having issues. It could also show low compression in some cylinders or excessive crankshaft end play — two problems that are expensive to fix. But if you don’t hear any clicking noises coming from the starter solenoid (which would suggest a bad starter), then a weak battery is likely to blame.

3. You notice a rotten egg smell when the car is running

It is normal for gasoline to have a slight gasoline odor when you are driving your car. If you notice that the odor smells more like rotten eggs or sulfur, this could mean that your battery is leaking hydrogen gas. This gas can be dangerous if it leaks into the car’s cabin, so get your battery checked out as soon as possible if you notice this odor.

4. The battery case has bulged or cracked

A bulging battery case indicates internal pressure built up by gasses generated during charging. This happens when there’s too much current coming from the alternator or not enough fluid in the cells to cover the plates inside them (that’s why it’s important to check levels regularly).

5. You see corrosion on or around the battery

If there is an accumulation of white, powdery substance around the terminals of your vehicle’s battery, it means that sulfuric acid has leaked from the cells. This is corrosion. Corrosion can prevent the current from flowing properly through the terminals and cause them to weaken. This can lead to several problems with your car, including the reduced functionality of electrical components like headlights and windshield wipers. Corrosion around or on top of the battery is often a sign that it’s time for a replacement.

6. You have to jumpstart your battery frequently

When you turn the key in your ignition, but nothing happens, it could mean that you have a dead battery. You can try jumpstarting your vehicle if you have jumper cables and another car nearby. However, if this happens regularly, your battery may be reaching its expiration date. Your battery should be able to provide enough charge for several weeks at a time. If this isn’t the case for you, it’s time to replace your battery.

7. Strange sounds coming from the battery

Have you been hearing some weird noises coming from under the hood? It could be a sign that your battery is dying and needs replacing. A failing battery will often make strange clicking and popping noises as it loses power. Other times, a failing battery will emit a hissing sound as acid inside boils and evaporates when it overheats or overcharges.

8. You check your battery with a meter — and it tests poorly

If your battery is in good condition, it should register between 12.4 volts and 12.7 volts. Anything below 12 volts is considered low, but anything below 11.8 volts is critical. Your friendly mechanic can check this for you, but if you want to do it yourself, you can purchase an inexpensive voltmeter at any auto supply store and use their instructions to figure out how to measure your battery voltage.

9. You’ve had your car battery for over 3 years

No matter how well-maintained it is, a car battery will lose its charge over time. The average lifespan of a car battery is three to five years, so if yours has been in service for several years already, set up an appointment with your mechanic to get it tested. Even if there are no signs of trouble yet, it may need to be replaced before long.


A healthy battery is crucial for every modern vehicle to start and run properly. A damaged or faulty battery can cause many problems for you and your car down the line. That’s why it’s important to pay close attention to any warning signs that your battery may be on its last legs

9354 Bandera Rd San Antonio, TX 78250 (210) 684-2277
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