Why Do Car Batteries Die When Not Used?

Your car’s battery functions in more ways than you think it does. That is why you might have noticed the battery losing power or dying even if you are not using the car for some time. But why do car batteries die when not used?

The car battery dies even if it was not in use because the battery still remains active. Almost all batteries have a self-discharge system, which is responsible for the battery losing its charge. Even if your car sits idle without the power running, this reaction keeps happening.

Car batteries can die at any moment. Even if it seems unusual to you, there are always reasons behind that. So let’s learn a thing or two about car batteries.

Why Do Car Batteries Die When Not Used?

Even before the pandemic hit the world and shut down everything, people would leave their car parked in the garage for days for various reasons. They would also leave cars parked at the airport when going on a long trip.

And after returning they would find that the car battery is dead. No matter how you leave it, it is not unusual for an idle car to lose battery power.

Well, truth to be told, the car battery is not unused. Even if you are not using the car, other functions are still active, such as the theft alert system, the climate control, or other electronic parts. Slowly, but they are using up the battery power.

Other than this, heat can decrease the battery power. Moreover, the self-discharge system causes chemical reactions in the battery, making it lose charge and die even without use.

7 Sign That Your Car Battery Is Dying

Car batteries die in one way or another. But if you cannot recognize the signs early, you may unexpectedly find yourself out of car battery power. So how do you know if your car battery is dying?

Here are some signs that you should look out for:

1. Dashboard Warning Light Is On

The dashboard warning light lights up to indicate various things. The light also comes on when the battery continues to run out of juice. So it is tough to tell if the light is warning about the drained battery.

• Slow Engine Start

Your car engine should start instantly. But if it takes longer to kick start, it indicates slow turning over of the shutter. So you should know that it is a sign of a dying battery. And slow engine start is the most common car battery dying symptom because the battery is trying to use its last bit of remaining power.

• Dim Headlights

If the battery fails to provide enough power, the electronic parts of the car will act up. And one of the first issues you will notice is with the headlight. When the battery power is low, the headlights will become dim.

• Electrical Problems

Your car battery is running many electronic parts of your car. The windshield wipers, dashboard lights, radio, power seats, etc., will not function properly if the battery fails to supply sufficient power.

• Swollen Battery Case

Since the battery is more like lots of chemical components put together inside a case, you can expect to notice changes in the box if something goes wrong. You will notice that the battery case looks swollen if the battery suffers from any such issue.

• Bad Smell

Have you smelled something rotten as soon as you opened the car hood after starting the car? This is a sign of a car battery leakage issue. It can happen if the battery suffers from any external damage and also if the battery has aged.

• Battery Is Old

Let’s not forget how the battery can act up if it becomes old. So if it has been around 3-5 years since you installed the battery, aging could be the reason why the battery is dying.

How To Prevent Car Battery From Dying When Not In Use?

Keeping the car battery unused is not going to save up its power. So to ensure the car battery stays charged, you can do the following.

• Instead of keeping the car idle, take it out at least once a week and drive for 15-30 minutes.
• Always ensure the battery is fully charged before you park the car for a while.
• If you are parking the car in a secure place, you can turn off the electronic parts so that they do not drain the battery.
•  If you notice any visible change in the battery case or it has any external damage, take it to a mechanic before it causes any more issues.

Frequently Asked Questions

Q. How long does a car battery last?

There is no fixed answer for this as different car batteries come with different lifespans. More than that, the battery’s durability depends on various factors, such as the usage, the type of vehicle it is in, the number of electric parts depending on it, and more. So depending on all that, a car battery usually lasts for 5 to 10 years.

Q. How long does a car battery last without driving?

If you leave your car with a relatively new and fully-charged battery, it will likely last two weeks before dying. But if the battery is old and not fully charged, it can run out of charge in a week or so.

Q. Should I disconnect the car battery if not in use?

You can disconnect the car battery only if you are going away for a long time, like a month or more. It is the best way to prevent the battery from running out of charge.

End Note

So, why do car batteries die when not used? The reason is simple: it is always in use. The battery is always running something in your car, even if you cannot tell.

To prevent the battery from dying like that, you can follow the tips I have mentioned. But if the battery keeps on dying frequently, the problem must be complicated. So the best thing to do is consult a professional to fix the issue as soon as possible.