How Long Can You Drive With Battery Light On?

If you have even seen the battery light come on while driving, you must have wondered how long can you drive with the battery light on before your car dies.

In order to find the answer to this question, you need to consider a lot of factors, which include the condition and age of the battery, how far you want to go, and your car type.

In most cases, the alternator is the reason behind this issue. Once the battery light comes on, it takes about 30 to 60 minutes for your car to freeze. 

First, you need to understand what it means to have the battery light on in order to comprehend the entire issue.

What does it mean to have the battery light on?

Just as with any battery, the 12-volt battery of your car will eventually die if it doesn’t get recharged. That’s why there is a built-in recharging system in your car. The battery is charged by the voltage regulator and alternator, which, while the engine is running, provides electricity to your car. If necessary, a typical alternator is able to generate 500 watts to 1,000 watts.

Your car is very much reliant on the battery. So, any car that has a 12-volt battery and a combustion engine is equipped with a light on the dashboard. This light informs the driver when the recharging system fails. In most cars, the light is shaped as a battery and somewhere it says “Battery”.

There is a circuit that monitors the voltage production of the alternator, and if there is low voltage, then it turns on the battery light. So, if you see the light on, that means the car is telling you that the alternator is not charging as it should.

When you start the car, the battery light turns on and even lingers for one or two seconds, but it goes away pretty quickly. However, if it doesn’t turn off while your car is running, this could mean there is some issue with the alternator. This could also indicate a minor issue with the battery. Doesn’t matter which one it is, you need to have it examined.

How does a car battery work?

The battery of a car contains chemicals that stock electrical energy. A car engine creates electricity by turning around a big magnet inside a coil of wire.

That electricity goes into the starter motor and cranks the engine to get it running. And after starting, a running engine recharges the battery by creating its own electricity.

There are two terminals on a battery: (+) positive and (-) negative. The engine is connected to the positive terminal while the negative one is connected to the car’s frame. The battery generates 12volts of electricity.

Six cells make up a car battery and each of them generates 2 volts, which takes the total to 12 volts. The cells are packed with electrolyte – a chemical solution. The electrolyte contains water and sulfuric acid.

The cells of a battery are connected together in a series, so the sum of individual cells’ voltage is the voltage of the battery. So, 12 volts is produced by the battery when all of the six cells are at work.

Each cell’s positive terminal connects to the adjacent cell’s negative terminal. This allows the current to flow in series through all six cells. Each cell comes with a plate constructed of lead dioxide and lead. The lead dioxide in the plate is porous, which allows the electrons to flow.

As a Conductive solution, the electrolyte helps to run the circuit between lead dioxide and lead plates. With the running engine, it reverses the current flow and restores the electrolyte chemical balance to recharge the battery.

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What happens if the battery of your car runs out of power?

When the battery of your car gets stripped off of its power, you will not be able to start your engine. Starting the engine again will require you to recharge the battery. You can use a charger to recharge the battery or you can connect your car with another car and use a jumper cable to recharge the battery.

When your car’s engine is running, it generates electricity that recharges the battery. If your engine is not running, eventually, the battery will run out of power. When this happens, you will have to recharge the battery to start the engine.

The power of the battery can also die out if it stays unused. This means, if you haven’t driven your car for a long time, your battery could die. So, before you can start the engine, you will have to recharge the battery.

Can the battery of a car run out while driving?

Yes, the battery power of a car can run out if the alternator fails. The battery gets recharged by the alternator when you drive. If it fails to work, then the battery will eventually run out of power, which will make your car stop. 

What are the warnings of a deteriorating Alternator?

If the battery of your car is drying up, it could be an indicator that your alternator is failing. Your battery gets recharged by the alternator while you drive. So, if the alternator is failing, then, sooner or later, the battery will dry up and the car will stall.

A few symptoms of a failing alternator:

• The battery light is showing
• The car is having trouble starting or stall
• The lights on the dashboard are flickering or dim
• Dim or flickering headlights
• Strange noises coming out of the car

How long can you drive with the battery light on?

Typically, the battery light indicates that the alternator isn’t properly working. As you already know, the alternator recharges the battery while the engine is running.

So, if it is not working, the battery will soon run out of power. But, how long can you drive with the battery light on? Typically, you can drive for about 30 to 60 minutes after the battery light turns on.

If there is any disruption with the alternator belt or if there is an issue with the alternator, the battery light will turn on. Since the alternator charges your car’s battery, if it breaks, the battery will not get charged. Although, the engine will still run. However, the car battery will run out of power eventually, which will make the car stop.

And if your alternator is defective, then the battery will not be charged by it even if the belt is undamaged. This will also make the battery run out of power as it is not receiving any from the alternator. And, eventually, the car will stop.

To fix your battery light issue, first, you need to know what is causing it. And the best way to know it is to take the car to a mechanic. They will check it and let you know what is causing the issue and how it can be fixed.

How to test the Alternator?

There are a number of ways to test your alternator, which will help you understand whether it is working properly or not.

Using a voltmeter to check the alternator is one way. Connect the voltmeter to your car’s battery and then start the engine. You should see a reading on the voltmeter that shows around 14 volts. If this isn’t what you are seeing, then there might be an issue with your alternator.

Using an ammeter is another method. Connect the ammeter coordinating the positive battery cable. You should see 30 amps reading on the ammeter with a running engine. If the readings you are seeing are not the abovementioned number, then there might be an issue with the alternator.

There is a third way to test your alternator, which involves using a test light. Connect the positive battery terminal and the test light. Touch the other side of the output terminal of the alternator. If your alternator is in good shape, you should see the test light brighten up. If it doesn’t, your alternator has an issue.

It is quite difficult to diagnose alternator issues as they are less likely to show up before the battery is almost dried up. If you find any indication that your alternator is faulty, then you should let a mechanic check it out. He will find out the issue and let you know what you can do to fix it.

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Conclusion

Now you know how long can you drive with the battery light on and what is causing the light to be on. The best thing to do once you discover that your battery light is on is to take the car to a professional for a checkup. He will find the issue and fix it for you.