What to Do If Your Car Battery Dies (& What Causes it?)

A dead car battery is something that no one wants to experience, but most car drivers will do at some point. Here's what to do if it happens and what can cause it

What To Do If Your Car Battery Dies

A dead battery can cause you to be stranded in dangerous places if it is not replaced or fixed immediately.

But what should you do when the car battery dies and what has caused my car battery to be dead suddenly?

In this article, we will go through exactly what you should do when your car battery is dead and find the causes of why it happened.

What to do when you car battery is dead?

If your car battery is dead, the best way is to charge it again with a car battery charger. If you do not have one available and are in a hurry, you can jump-start it with another car. You can also use a jump starter if you have one available.

There are some different ways you can handle the situation with your dead car battery, depending on how in a hurry you are and what tools you have access to. Here’s a more detailed list of what to do if your car battery is dead:

1. Jump-Start from Another Car

Jump Starting Car

When your car battery is dead in emergencies, the best thing to do is jump-starting it from another car’s battery.

The only thing you need to jump-start is another car with a working car battery and a pair of jumper cables. If you do not have a pair of them in your car, I strongly recommend getting a pair.

The jump-starting is pretty straightforward, but you have to follow it closely not to cause any shorts, which may damage the cars.

  1. Put both cars in park or neutral with the handbrake. Open the hoods of both cars and locate the car batteries. Remember that some cars can have their car battery located in the trunk.
  2. Attach the red jumper cable to the positive (+) terminal of your car battery and the other end to the other car’s positive (+) terminal.
  3. Attach the black jumper cable to the negative (-) terminal to the other car’s battery first. Then you can connect the other end of the cable to a metal-clean surface on your car’s body or at the engine. You can also attach it to the negative (-) terminal of your car battery if you can’t find any other place, but it is not recommended.
  4. Start your car and let it run for a minute.
  5. Begin with removing the negative jumper cable from any of the cars.

Next time, I recommend you get a jump starter to keep in your glove box, which will make the situation much easier the next time.

2. Recharge the car battery

Charge Car Battery

If your car is parked at home and not in a hurry, it can be a good idea to charge your car battery slowly. Slower chargings are much better for the car battery than jump-starting it.

RELATED: How Long Does it Take to Charge a DEAD Car Battery?

3. Replace the car battery

Car Battery Check

Car batteries should usually be replaced every 5 years. If you feel that the car battery is very old, it may be a good time to replace the car battery instead of recharging it, which may cause the same situation again shortly.

4. Diagnose what is drawing power.

Best Car Battery Testers

After you have started your car, you have to find out what caused the car battery to die suddenly, or otherwise, you may end up in the same situation again.

Below, you will find more information about what can cause the car battery to die suddenly.

8 Causes of a Dead Car Battery

The most common cause of a dead car battery is that you forgot any electric consumer on. It can also be due to a faulty electric consumer which won’t shut off when you remove the key from the ignition. It can also be caused by cold weather.

Here is a more detailed list of what could cause a dead car battery.

1. You forgot any electric consumers on

Car Light Switch On

One of the reasons for an empty battery is human error. There are moments when you are in a hurry and forget to turn off the lights or close a door properly before leaving the vehicle. If the headlights stay overnight or for a few hours, they drain the battery, and your car battery will be dead in the morning.

However, modern cars have warning signals when you leave the headlights on, such as a beeping sound, but it can definitely be missed if you were in a hurry.

2. Electric consumers are drawing power

Car Stereo On

Did you recently install some external electronics to your car, like a car stereo or a GPS? Then there is a chance that you wired these devices wrong, which will cause them to stay on even after you turn the ignition off.

It can also be caused by any faulty consumers who are not shutting off when you switch off the ignition. However, this can be difficult to diagnose, and you might want to let an expert looking at it with the right equipment.

3. The alternator is going bad

Alternator Location

The alternator’s job is always to charge the car battery while you are driving. If the alternator is starting to go bad, it may not charge the car battery properly, and within time, this can cause the car battery to drain out.

You can check the alternator by measuring the car battery voltage on idle. You should get over 14 volts if your alternator is in good shape.

4. Cold weather and a low charged car battery

Cold Weather Car

Was your car standing outside while it was freezing weather? Car batteries can actually freeze if the weather is very cold. This especially happens if your car battery is not fully charged and especially if it is empty.

The cold may actually have killed your car battery, and in this case, you have to replace it.

5. You only drive short distances

Drive Car 2

Many people do not use their car a lot. This causes your car to only being driven for short distances. As you might know by now, the alternator is always charging your car battery while driving.

If you only drive short distances, the car will draw more power than the alternator will have time to produce, and this can cause the car battery to drain out and die completely.

6. Lack of car battery maintenance

Fill Car Battery

Car batteries actually need maintenance to have a long life. This includes cleaning the terminals, filling with battery water (if the battery has this refilling holes), and maintaining recharge your car battery quite often.

If you never did any maintenance to your car battery, it could absolutely be the cause of your dead car battery.

7. Car Battery went bad

Bad Car Battery

It happens that your car just went bad because of age. A car battery has an average lifetime of around 5 years, and if it hasn’t been changed within this timeframe – there is absolutely a chance that your car battery is just old and needs to be replaced.

You can often check your car battery’s condition with a car battery analyzer.

8. Corroded or Loose Battery Cables

Corrosion Battery Terminal

It can actually happen that your car battery is, in fact, not bad at all; it is just a bad connection between the car battery terminals and the battery cables.

This is often caused by corrosion on the terminals and can easily be cleaned with acid.

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Written by:

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.