After their car battery died while they were driving, many people wonder if the car battery can die while driving. Obviously, the answer is “Yes, a car battery can die while driving.”
Although it is a rare occurrence, a good car starting or dual-purpose battery shouldn’t fail while you’re on the road. There are many reasons why a car battery dies while driving, here are the few most common ones…
Table of Contents
The Role of Your Car’s Battery
Your car’s battery serves as the source of all power. In other words, your battery is necessary for any devices that depend on current. It will be directly connected to your battery and continue consuming power as long as the component is operational.
The battery will continue to supply power to the radio until it shuts off or the battery runs out, even if your car isn’t moving but the radio is still on.
Your battery’s primary job is to start your car when you turn the key. Since the alternator isn’t yet firing, the battery must perform this energy-intensive task on its own.
Car Battery Died While Driving: Causes & What to Do
Depending on whether the alternator/charging system is functioning properly or not, a car battery can die while you’re driving, and the vehicle will eventually come to a stop as well.
If the engine is On and the car is driving, there are several potential situations:
- Battery died (short circuit cell), alternator/charging system is working properly: The alternator is typically able to maintain a high enough voltage in this situation so that the car’s servos, lights, radio, fans, etc. can function as intended.), but as soon as the engine is turned off, the car can’t start again. Drive to the authorized car workshop to have the vehicle inspected if the electronics in this case indicate a dead battery or any other battery issue while the engine is still turned on.
- Battery died, and the alternator/charging system is not working properly either: in this situation, it is only a matter of minutes (seconds?) when the onboard electronics will turn the engine off, or the engine will simply stop working.
Note: older engines, especially diesel with mechanical high-pressure injection systems, may even continue to work for longer period of time, but it is anything but safe and/or recommended to continue the drive in such condition …
- Battery is fully charged, and the engine is on, but the alternator/charging system died: in this situation, onboard electronics will probably signalize an issue with the charging system and display either warning or error and tell the driver to either go to the workshop or to stop the vehicle right away. Older vehicles will initially function normally, at least in the beginning. However, after some time, the lights will dim, the fans will turn more slowly, the radio or multimedia speakers won’t be as loud, etc.
However, sooner or later, the car will come to a stop. In the worst case, one loses the steering and brake servos at the exact same time the car’s engine shuts off while it’s still moving.
Don’t panic; instead, turn on your emergency lights if your battery still has some power, and stop your car. Be aware that the steering is harder and that applying the breaks will require more force to bring the car to a stop (use the emergency brake if necessary).
When you stop, try to start the engine a couple of times while keeping an eye on the dashboard and the warning lights and error messages. Cars rarely have transient errors (some dirt in the fuel, for example), but if you manage to restart the car, perhaps you are lucky to have such a “transient” error – nonetheless, as soon as possible, drive the car to the repair shop to check what happened.
The majority of the time, there is nothing one can do to fix a car on the open road, so if the car cannot be started again, secure the vehicle while keeping yourself and your passengers as safe as you can. Then, call a tow service to tow the car into a car repair shop.
Why use a certified auto repair shop? There are many explanations, but to put it briefly, they are competent.
Additionally, a dead battery can harm other electrical systems, so it’s important to thoroughly check the car’s diagnostics in addition to simply plugging the laptop into the diagnostic port…
Note: after January 1, 1996, all cars built and sold in the US are required to be “OBD II” compliant (On-Board Diagnostics System II) – if you have an older than that vehicle, personally, either drive it to the museum or the scrapyard 😉
Older and classic cars, of course, are exempt from this…
Signs That Your Car Battery is About to Fail
The alternator powers the engine and recharges the battery while you’re driving your car. The power will only suddenly cut out if your battery dies and the alternator fails.
Other signs that your car battery is about to fail include:
- Engine struggles in lower temperatures
- Dim interior and exterior lights (or they won’t turn on)
- Engine turns over more than three times when starting
- Radio doesn’t stay on or has poor signal
- Corroded, damaged, or loose battery terminals
- Battery is more than five years old
A quick do-it-yourself fix is to change the battery if you’re certain that’s what’s wrong. You should take your car to a mechanic as soon as possible, though, if the issue continues even with a new battery. Delay could result in more severe internal harm.
What Happens If Your Car Battery Dies While Driving?
Nothing will happen while you’re driving if your car battery dies but your alternator is still in good condition. Remember that your battery is being charged by the alternator.
The alternator can handle all of the demanding work as long as your engine is running and the electrical demand is low enough. So even if your battery dies, your car will still run.
The key is to turn off your HVAC system and high-use appliances like your stereo speakers. As a result, your alternator will need to produce less electricity on its own.
In order to give your battery more power if your car is having trouble, you can put it in neutral and rev the engine a little. When you completely stop, you could also encounter issues. Your alternator performs best when the car is moving, not just sitting still.
You will require a jump start the next time you want to start your car because the battery is dead. If you want to avoid asking a complete stranger for assistance, you can use a portable car jumper.
What to Do If Your Car Battery Dies While Driving?
You may be quite frightened now that you’ve read about what can happen if your car battery and alternator fail while you’re driving. The good news is that once this occurs, the process is fairly simple. Since I’ve been through it, I’ll tell you what I did:
Pull over Quickly
The first thing to do is move as quickly as you can to the side of the road. The gas pedal in your car won’t work. You won’t be able to activate your hazards or headlights, and the power steering will not be working.
Pay attention to stopping your car. It’s safer to do that than to try to coast in a car without electricity, even if that means having tires in the grass.
When you are out of traffic, you can begin looking for a solution.
Set Up Roadside Flares
If it’s nighttime, there will be no way for passing cars to see you because your car won’t have any lights. I would advise setting up roadside flares as a result. You’ll have them on hand if you put together an emergency bag.
To be ready for the next time, use my advice if you don’t already have an emergency car bag.
If you don’t have flares, you should exit your vehicle and move away from the situation. You won’t be protected if your car is stolen because your airbags won’t deploy if it has no electricity.
Try Restarting Your Car
Sometimes all you have to do is start your car again and go. Although it’s rare, I’ll admit it’s worth a shot.
Once your car has successfully started again, turn off the AC, radio, and all other electrical devices. Before returning home, you’ll need to reduce how much electricity your car uses.
Get a Jump-Starter
You might need a quick jump to get home if it doesn’t restart. Start trickle charging your battery if you have a portable car jumper by plugging it in.
This charge will not last very long because the alternator is dead. It is hoped that you will have enough to make it safely home before moving on.
I wouldn’t even try to jump start your car if you were still far from home. You can only use the energy produced by the jump because a dead alternator won’t allow your battery to recharge.
Tow Your Car and Repair It
You were either able to crawl back home at this point, or you were still stranded on the side of the road. You should call for a tow to a local mechanic in either scenario. The best course of action is to have a mechanic replace the alternator because it is a fairly challenging repair.
Inform them that your alternator may be defective. Depending on how badly damaged it was during the discharge, they’ll replace it and may even change out your battery.
Understand the Alternator
How does your battery charge if you don’t plug your gasoline vehicle in at the end of the day? The alternator plays a role in this.
A small motor powers the alternator. It is connected to the battery and powered by the engine of your car. The alternator generates electricity as your engine turns and directs it into the battery to reverse charge it.
Sometimes, even when the battery is completely dead, a functioning alternator can keep a car running. This is only true if the alternator can generate enough energy to supply all the electrical components that require a charge.
What Happens If Your Alternator Dies While Driving?
A failing alternator while you’re driving can have much more disastrous consequences. In actuality, this is likely what most people picture when they think of a dead battery. I can attest that it is not fun at all to have an alternator fail while you are driving.
Engine Dies
Your car’s engine will immediately stop running, first and foremost. As the alternator begins to die, you might notice it sputtering a little bit. Your engine will simply shut off once the alternator wears out and the battery runs low.
It resembles stalling a manual car in many ways. The gas pedal will do nothing as you lurch forward. Instead, you’ll begin to slow down while rolling.
Lights Turn Off
The lights in your home will also all go out. This includes any dashboard and dome lights as well as your headlights. It was the middle of the night when my alternator broke, making it extremely dangerous to try to drive through the backroads in total darkness.
None of the lights in your car will illuminate because it is powerless.
Power Steering Disappears
The power steering is yet another system that is electrically controlled. Pumping fluid requires a certain amount of power in order for it to function.
When the alternator is turned off, you’ll need to pull on the steering wheel the old-fashioned way. This can be extremely shocking and unsettling if you’ve never driven an old car. Keep in mind to turn your steering wheel using the hand-over-hand technique.
Radio, HVAC, Dashcam, Etc. Will Stop Working
In fact, after your battery and alternator fail, every electrical part will fail. Your phone charger, radio, AC, dashcam, heated seats, and other amenities will all stop working at once.
Anything that needs electricity won’t function at all, including the apps on a phone whose battery is dead.
How Long Should Your Car Battery Last?
A typical lead-acid car battery should last between three and seven years, depending on your location and the battery and how you’re driving. The battery’s lifespan is shorter in colder climates!
Of course, you can spend your money on an AGM or gel battery instead, as those have a much longer lifespan—often between 5 and 10 years! However, it still depends on where you are, so to get the most out of the battery, use it frequently and keep it charged.
But, how long does a car battery last without driving? Read it here!
Troubleshoot a Car Battery That Dies While Driving
You must be aware of how to troubleshoot a car battery that keeps discharging when you are driving. If not, it will continue to occur or, even worse, you will end up replacing the wrong component.
Disconnect the battery and charge it completely before continuing. While auto parts retailers like AutoZone will test your battery for you, they won’t be able to provide an accurate reading unless your battery is fully charged.
You shouldn’t test the battery to see if that’s the issue until you have a fully charged battery. If so, you should replace it, though you should also examine the rest of the system. You should have the alternator checked for you if you bring your car to AutoZone or another parts store. The likelihood of your battery dying while you’re driving is very low, so if it’s charging the battery, that shouldn’t be the issue. You should also check for a parasitic draw, though, as there is one more thing.
When everything should be off, a parasitic draw draws energy from the battery. You might make an incorrect diagnosis if the battery keeps dying once you start driving.
Open the hood, turn off the engine, and unplug the negative battery terminal to check for parasitic draws. After letting it sit for about 5 minutes to drain any remaining power, connect your multimeter.
Put the red lead on the “Amp” reading, then put one lead on the negative battery terminal and the other on the end of the negative battery cable. If it is greater than 50mA, you have a parasitic draw, which is probably what is draining your battery.
Final Thoughts
When your car won’t start, it can be frustrating, but hopefully after reading this guide, you can put those days behind you forever. Take your car to a qualified mechanic, though, if you’re unable to identify the issue.
If your battery keeps dying, it will put extra strain on your car and require more repairs.
