Why Does My Car Battery Keep Dying? (11 Reasons Why)

So why does your car battery keep dying? Well, it might have something to do with all those bad habits we have as vehicle owners.

Your car battery is your vehicle’s power source. Therefore, you must have a functioning alternator along with it. However, they can cause issues when they go out of order. Here are 11 potential reasons why your battery keeps dying!

Why Does My Car Battery Keep Dying?

1. Old And Weak Battery

A battery is an essential part of a car and is responsible for starting the vehicle. If you have a dead battery, you will not be able to drive.

Because of this, you need to check out the age of your battery; it will most likely be old and weak if it has been sitting around for a long time without being used up.

As well as that, fuel may build up in the engine’s cylinders due to weak sparks produced by a dying car battery.

As a result, the battery has reached its limit and will eventually die as its voltage decreases.

2. Inefficient Charging System

The battery, voltage regulator, and alternator are the three components that make up a charging system.

Besides that, keeping the battery charged and powering the car’s electrical accessories are the two main goals of a charging system.

On the contrary, if you encounter an inadequate charging system, a bad alternator is the most frequent cause.

Therefore, if the battery charging mechanism fails, your vehicle won’t be able to generate or hold a charge.

3. Headlights Left On

If the interior car lights are left on throughout the night, the battery won’t run out of power until 27 hours have passed.

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In this case, the car battery usually gets drained if you leave the headlights on for a long time when the vehicle is not moving.

Consequently, the battery can only be kept charged while the engine is running and in driving mode.

After all, leaving the lights on in your car will deplete the battery, which could result in stalling or even the inability to start your vehicle.

4. Parasitic Drain

Parasitic drain is the amount of energy drained from your battery while it remains connected to a device like an air conditioner or power outlet.

Along with this, the acid corrodes the battery’s plates and causes them to wear down faster than they should.

Through that, the car’s alternator can’t supply enough current to keep up with the demand from your car’s electrical systems, so it can’t charge up as much as it needs to.

As a direct result, your alternator constantly draws power from your battery, which can lead to an early death for your battery.

5. Damaged Alternator

An alternator is what powers your car when its battery runs out of charge.

In addition, the alternator is responsible for charging the battery when its voltage drops too low.

So, when the engine is running, the alternator charges the battery, and once the battery is empty, the car will not start.

Due to this, a damaged alternator can only keep a car running for a short period.

Therefore, the alternator might not keep your battery fully charged, and your vehicle can stall out frequently.

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6. Substandard Chargers

Substandard Chargers

Car battery chargers are beneficial for keeping the batteries operating when needed.

As well as that, it ensures that your battery is fully charged before you use it to start the vehicle. Also, it avoids deep discharges that could prematurely damage your battery.

As a result, local or defective chargers risk not only giving a poor charge but possibly destroying the car’s battery.

7. Deteriorated Battery Cables

When your battery cable starts to deteriorate, it’s often because it’s been exposed to some damage.

Apart from this, if you have a car with older-style cables, it typically has a much lower melting point than aluminum.

Over time, this will cause corrosion and degrade the integrity of your cable and won’t be able to hold up against a load of your alternator, leading to the death of your battery.

8. Short Routes

Making frequent short trips in your vehicle can result in a battery that struggles to keep a charge and progress to a shorter lifespan.

Additionally, it prevents the car battery from ever having the chance to complete its most energy-consuming task of full charging.

When in doubt, preserve a decent charge by driving around for around ten minutes.

9. Extreme Weather

Cold temperatures can drain batteries faster than average, so if you’re taking long trips in cold weather, keep an eye on how much juice is left in the battery.

Consequently, if you live in an area where temperatures frequently drop below freezing, consider getting a new battery that will keep it at a comfortable temperature year-round.

Of course, you don’t want to be stranded with a dead battery!

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10. Overcharging

Overcharging your battery can be caused by human error, such as failing to comprehend how to use a car battery charger or choosing the incorrect voltage.

Furthermore, your car battery may drop if you leave your charger unattended overnight.

As an outcome, if your battery is overcharged, your car batteries could suffer greatly, leading to perishing.

11. Extreme Application Of Car Lights

Interior lights, door lights, or even faulty relays can deplete a car’s battery when it is not in use.

In most cases, the alternator recharges the battery while your engine is running, so you usually don’t have to worry about the battery dying.

That said, the excessive use of your vehicle lighting systems causes battery loss of life.

To know more, you can also read our posts on why car batteries corrode, why your car smells like antifreeze but not overheating, and why Liberty Mutual is so expensive.


The truth is car batteries occasionally fail. And because of their price, getting a replacement when they break may be frustrating and inconvenient.

As demonstrated, variables such as an old and weak battery, an ineffective charging mechanism, and headlights that are kept on might reduce its lifespan.

At the end of the day, it really comes down to you doing a basic diagnostic check to find the specific problem with your car batteries.

2 thoughts on “Why Does My Car Battery Keep Dying? (11 Reasons Why)”

  1. Great post!
    Found the reason why my car battery keeps dying. That’s because I used the incorrect voltage for my battery. Am I dull? 😀
    But, why don’t you add some tips to maintain the battery to help readers reduce the replacement cost?

  2. Hi Tristan,
    I had a suggestion for your blog post, and I tried contacting you via the contact page 2 days ago.
    Just wondering if you had a chance to take a look at it.
    Please share your thoughts.
    Have a good day!


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