Why Does My Car Battery Keep Dying?

There are countless potential causes for a dead car battery. Still, almost all of them can be boiled down to three main types: faulty batteries, electrical system malfunctions, or simple human mistakes. Some may be fixed at home, while others may necessitate a trip to the shop, but you won’t know for sure unless you get your hands dirty and get to work.

In comparison, many individuals talk of a battery dying repeatedly. For example, they refer to situations when the car won’t start after being parked for an extended period. In addition, your battery might be dying while driving, which indicates a problem with the charging mechanism. In this article, we will acknowledge why your car battery keeps dying.

Why Does My Car Battery Keep Dying?

Your car battery might keep dying due to Loose and corroded battery connections, Electrical Drains, Charging Issues, increased power requirements, or harsh weather conditions.

Headlights, dome lights, and other accessories can be powered by a car’s battery when the engine is off, although it has a minimal capacity. This implies the battery will quickly drain if anything is left on after turning off the engine. Even if you only conduct a quick errand like grocery shopping, leaving the headlights on quickly drains a weak battery. However, even a little interior dome light can quickly drain a battery. The best time to inspect a battery that keeps dying is in the middle of the night when it is pitch black and you can see a feeble dome light.

When you remove the keys and turn off the engine, some modern cars temporarily keep the headlights, dome light, or radio on. When everything is operating correctly, it is possible to walk away from a vehicle like this and shut it down on its timetable. However, if you return 30 minutes or an hour later and specific lights, such as the headlights, are still on, your battery may be running low.

Can Your Battery Die While Driving?

Yes, your battery might die while driving. However, a dual-purpose battery should not die while going, although it might die in rare events.

If your battery has died but the alternator is working correctly, there are some situations when the alternator can keep the voltage adequate so that the car functions properly. But when the engine is switched off, it can no longer start. If the electronics indicate a dead battery or other battery issue or the engine is still running, take the vehicle to an authorized auto repair shop for inspection.

If your battery died, but your alternator is not working correctly. Depending on how quickly the onboard electronics shut down the engine, a few seconds or minutes are all it takes for the engine to stop working. In particular, diesel engines utilizing mechanical high-pressure injection systems may still run for a long time. Still, it is unsafe or suggested to continue driving in such a situation.

If the battery is fully charged but the alternator is dead, the onboard electronics will most likely display a warning or error message and instruct the driver to go to the shop or come to a complete stop if they detect a problem with the charging system. It’s common for an older car’s systems to function after it’s been serviced; nevertheless, with time, the lights darken, the fans slow down, and the radio/multimedia speakers grow less loud.

Regardless, the automobile will eventually come to a halt. If the engine dies while the car is still moving, it is possible to lose the steering or braking servo simultaneously. If something happens, don’t freak out; switch on the car’s emergency lights and pull over. Remember that the steering is more complicated and that you must forcefully apply your brakes to bring the vehicle to a complete stop.

What to Do When Your Car Battery Dies?

If your car battery is dead, try jump-starting it. Jump-starting a dead battery is the most popular method of reviving it. A set of jumper wires and a working battery from another vehicle are all you need to jump-start a car. However, it is not recommended to attempt to jump-start a vehicle if the battery is damaged and leaking acid.

One of the most annoying things that can happen to a car owner is discovering that their battery has died, which never occurs at a convenient moment. However, we’re here to assist you in figuring out what went wrong and what to do next time it happens.

Acknowledge the following steps to jump-start your car-

  1. Jumper cables are always a brilliant idea to keep in your car’s trunk.
  2. Please switch off the ignitions of both vehicles and park them safely.
  3. Attach the the red car clips to the batteries. Attach the red car clip to the positive terminal of your battery, and then attach the other red car clip to the positive terminal of the other car’s battery.
  4. Attach the Black car’s clips to the batteries. First, attach the black car’s clip to the negative terminal of the other car’s battery, and then attach the black car’s clip to the metal struts that hold your bonnet open.
  5. Once this is done, start your car and check if the engine will start. If not, ensure the clips are securely fastened and run the other car’s engine for at least 5 minutes. If it still won’t start, the battery may need to be replaced.
  6. If your car starts, don’t shut off the engine. Instead, drive around for 15 minutes and recharge your battery.

What Can Drain a Car Battery?

Your battery might drain due to an Ineffective charging system, Electrical Glitches, Corroded Alternator, or even an Expired battery.

Poor installation, defective fuses, and defective wiring are all possible causes of electrical malfunctions in your automobile and batteries. It can cause the typical and anticipated parasitic drains on the car battery, which deplete the battery while the car is off, to become excessive & drain the battery. It’s common knowledge that your car battery supplies electricity to various components so that they continue to function even after you’ve turned off the engine. The security alarm, radio settings, and clock are all included. However, suppose we extend these regular parasitic drains to o. In that case, e, her automobile components, such as turning on the glove box lights. As a result, while the automobile isn’t running, the battery is being depleted similarly.

A drained battery whenever the car is parked or, worse, a rapidly depleting charge while driving might result from a malfunctioning charging mechanism. Both weak connections and rusted tensioners might lead to an inefficient charging system. This signifies that your automobile battery isn’t charging correctly and its power is lower than planned. In this scenario, imagine a battery that has been low in charge and used to power the car’s “parasitic” components while the vehicle is parked. Isn’t your battery going to run out of juice at some point?

Can Heat Kill Car Battery?

Yes, heat can kill your car battery. The high temperatures might evaporate the battery and its vital liquids and weaken the charge. They can even speed up the corrosion process.

During the summer, life seems more difficult. When you’ve just walked a few blocks, all of a sudden, you’re thirsty! In the heat, your car battery might also suffer from a lack of water. The critical liquids in your battery might evaporate and degrade their charge if exposed to high temperatures. Furthermore, corrosion can be accelerated by high temperatures. You can’t reverse damage caused by corrosion to the battery’s internal structure after it’s “parched,” making it much more dangerous.

Be aware that most automotive batteries are self-maintaining. The water level can be seen through a window or a water level indicator. As a result, starting a car in the winter won’t be nearly as challenging for a heat-depleted battery. Batteries damaged by overheating die much more quickly in the cold.

Does Leaving Your Inside Car Lights On Drain the Battery?

Yes, leaving the inside car lights on drains the battery. However, remember that if you leave your car lights on overnight, you risk draining your battery to the point that your car won’t start the next day. The battery has to work overtime to keep your car’s lights on while the engine is not running.

We forget to switch off the headlights, interior lights, or both when we leave the vehicle. The only thing you want to come home to after a long day’s work is in the comfort of your warm bed. Instead, you wake up the next day to a car that won’t start or a car with its lights on after a bad day. Leaving your car’s lights or headlights on for lengthy periods without the engine running drains the battery. Charge your phone, play music, and switch on the headlights & interior lights while driving since a car’s battery is recharged while moving. Cars recharge their batteries when they’re running.

If you leave your headlights or other lights on, your automobile will likely make it through the night. Your battery draws energy from your lights without recharging them if your lights are on. Even if you return in the morning to check on the headlights, it is pretty unlikely that they will still be on. The lights are automatically turned on whenever the automobile detects a problem. To avoid returning to a non-starting vehicle, close all doors before leaving your car.

Your car’s battery won’t be able to keep your car’s systems working for long periods without being recharged by the engine. The engine recharges the battery to maintain its charge when driving your automobile. Ensure your battery is still in good working order if you’ve saved the lights on in your car too long. Even if your battery is dead, your day can carry on as long as you have enough juice. Remember that if you leave your headlights on overnight, you risk draining your battery to the point that your car won’t start the next day.

You’ll notice that your car’s battery will deplete if you leave the lights on while the engine is off. Your battery’s state will determine whether you need to purchase a new one or recharge the one you currently have. Unfortunately, because battery problems come under maintenance and your policy does not include maintenance, your auto insurance will not cover the cost of a replacement battery or vehicle towing. So even though it was an accident that you left the lights on, you’ll be on the hook for the whole bill.

Can a Blown Fuse Drain Your Car Battery?

No blown fuse cannot drain your car battery. A blown fuse prevents any current from flowing through the system. It’s impossible to drain the battery that way. Instead, you should do a “parasitic draw test” to find your car battery’s leakage draining.

A blown fuse interrupts the flow of electricity via the circuit. However, there is no way to deplete the battery by blowing a fuse. Bring the battery in to be tested; the problem may be with the battery itself. Is it possible that a blown fuse may prevent my car from starting? In many cases, a blown fuse will only result in a minor issue with your car’s electrical system, such as the inability to operate your radio, a malfunctioning turn signal, or most climate control capabilities. On the other hand, a blown fuse might cause your vehicle to fail to start in some instances.

Underhood, trunk, headlights, and glove box lights that don’t switch off when the door is closed are the most prevalent culprits for parasitic drains. Switches trapped in the “on” position can cause a battery to be drained. A parasitic battery drain happens when an unexpected and persistent loss of power occurs after turning off the engine. An electrical short circuit or an electrified device, such as a trunk, is the most common cause: a glove box or under-hood light.

Does Cold Weather Kill Car Batteries?

Yes, cold weather kills car batteries. Car batteries expire in cold temperatures for various reasons, including reduced capacity. Battery capacity is reduced by 20% at 32 degrees in cold weather and drops by 50% at -22 degrees. When the battery’s capacity decreases, the battery’s ability to start the vehicle also decreases.

Prolonged exposure to sub-zero temperatures can seriously harm car batteries. Summer heat causes a battery’s crucial fluid to evaporate, setting the stage for winter’s more challenging chore of shutting down the battery’s chemical processes. Many batteries will withstand the cold weather, but others will not. Find out why your car’s battery dies in the winter so that you can plan.

Consider the difficulty of sucking molasses via a straw. In the winter, your automobile battery experiences something similar. Temperatures drop, and the oil in your engine thickens. Driving a vehicle with thicker oil takes more power than a thinner oil. As a result, it can be challenging for batteries that are more than three years old.

To avoid this cold-season problem, make sure the battery has the correct CCA value, or “cold-cranking amps,” for your area. This value reflects the battery’s ability to start an engine in sub-zero temperatures. If you have a higher CCA level, you’ll be able to withstand cold weather better. Using synthetic motor oil with such a higher cold tolerance can also help extend the life of your battery.

Can You Jump a Battery With a Dead Cell?

No, you cannot jump a battery with a dead cell. Having a dead battery means there’s no residual charge left, and the other cells are constantly drained of power. As a result, dead cell batteries will not take charge and thus cannot be jump-started.

When purchasing a car battery, look at one with a cold crank amperage of 12 volts DC. It tells you how much low-down power the battery has to start the engine in freezing conditions, measured in amps. Due to their high torque requirements, more significant gasoline and diesel engines are often combined with high-amperage batteries.

When the amperage rating of a car battery drops below a certain threshold, the vehicle’s engine will not run. For example, if a battery is tested and shows 12 volts across it but does not have enough cranking amperage to start an automobile, the battery is defective. If the battery drain was left on because the lights were left on, recharging it will fix the problem. Typically, a two-year-old battery will no longer accept an electrical charge and can no longer crank the engine. In this scenario, the battery can no longer hold enough amperage and voltage to power the engine’s electrical systems, even if you attempt to jump-start it.

A flat battery is not the same as a dead battery. Flat batteries may be jumped from another battery or pushed started and will continue to perform effectively once charged by the vehicle’s alternator. A dead battery means there is no residual charge remaining and that the other cells are constantly being drained of power. Also, jump-starting isn’t possible with dead batteries since they won’t accept a charge.

Can Battery Corrosion Drain a Battery?

Yes, battery corrosion can drain a battery. However, battery corrosion is commonly found at the terminals and can be removed via careful cleaning and oiling.

Corrosion can reduce a battery’s life. It is a common problem that you may remedy with a thorough cleaning of the battery terminals. Corrosion prevents the battery from receiving an adequate charge during charging and will not supply your vehicle with the necessary charge. However, corrosion may not immediately affect the battery’s charge capacity.

You can remove battery corrosion with a stiff-bristled brush, baking soda, and water. However, no baking soda must enter the battery cells during this process. Additionally, if you leave a mixture of baking soda and rust on your driveway or garage floor, you might finish up with a hard or impossible stain to remove. You may clean battery terminals and cable connections of corrosion using sandpaper or a specialized tool.

For the most part, these instruments are simple wire brushes. Battery terminals will seem cleaner and brighter after using these tools; you’ll also notice a significant improvement in the electrical connection. Additionally, the battery connections must be secure. If you discover that the battery wires are loose, you may have found the root of the problem. You may trace ground & power battery wires back to the frame, starter & junction block, and fuse box. Check these connections for corrosion and ensure they are secure.

Car Battery Keeps Dying?

Your battery keeps dying due to faulty charging systems, Old Battery, Corroded Battery Cables, Defective Alternator, Leaving Lights On, and Parasitic Drains.

After the engine is shut off, the battery is still being drained by a parasitic drain or draw. In most cases, the problem is caused by an electrical or wiring fault that prevents specific electrical components from shutting down, resulting in the battery draining uncontrollably. Keeping an eye out for this energy drain is essential since it may slowly but surely drain your automobile battery. Additionally, this might signify a faulty battery or even a blown electrical circuit.

It’s up to the alternator to use mechanical power to replenish the battery when it disengages. The car’s electrical system is kept up and running with the alternator, including its lights, radio, air conditioning, etc. A foul diode in the alternator means it won’t recharge the battery entirely, which will appear in the car’s electrical components. A defective alternator may be causing electrical problems when the car is idle, but it is OK once you get in the driver’s seat.

As humans, we all tend to make mistakes. It is perhaps the most prevalent and primary cause of overnight battery drain. We’ve all been guilty of leaving the lights on when we arrive home late from a night out. You don’t put the lights on for more than 5-6 hours, inside and out. A fully lit automobile for 10-12 minutes is enough to drain the battery’s power; however, any power use beyond that could leave the battery undercharged. Light alert and auto-deactivation features are standard equipment in today’s new automobiles. The lights may be left on, but finding a dead battery while running late for work is not enjoyable.

How Do I Find Out What’s Draining My Car Battery?

You can find out what draining your car battery is by checking for a parasitic drain.

You may also have a drain on a system that continues after you remove your keys and lock the doors, which is a simple explanation for why the car battery keeps dying repeatedly. There may be a drain in your system, even if you’ve previously ruled out items like headlights & dome lights. Checking for a drain is as simple as disconnecting a battery cable and observing the flow of electricity. For this reason, use the highest feasible amperage setting on a multimeter. If you don’t, you risk damaging your meter’s pricey fuse. Testing for current flow without unplugging anything is crucial by using an inductive clamp on some meters.

You may also use a test light to check for a drain, which is less accurate. The negative battery wire must be disconnected, and a circuit must be built between the negative battery terminal and the ground. If the test light is on, there is a drain in the system that you must fix. The drawback of utilizing a test light is that even the intensity of the light makes it harder to determine how much drain is there.

The trunk, glove compartment, or other malfunctioning lights are among the most typical sources of a parasitic drain. If these and many other interior lights fail to switch down, they can kill a battery overnight. To find the source of a parasitic drain, you must first eliminate all other possibilities. To make this diagnosis, you may keep the multimeter or test light attached and remove each fuse until the drain is stopped. Identifying the relevant circuit can help you pinpoint the component malfunctioning component.

How Do I Know If My Alternator Is Draining My Battery?

You can know if your alternator is draining the battery, if your headlights are flicking, if there are strange sounds if you have difficulty starting your car, and if you face electric failures.

According to It Still Runs, headlight fading is one of the first indicators that the alternator is malfunctioning. If you observe that your headlights go brighter or darker as you increase or reduce your engine speed, this is a warning sign. If your alternator operates well, your headlights will shine brightly no matter how fast you’re going. Additionally, your headlights may begin to fade or get weaker. Dim lights on the dashboard are also a sign of a problem. Your alternator may no longer be able to generate enough power if it begins to flicker or get dimmed.

Having a weak or dead battery might indicate a problem with your alternator. Battery replenishment is possible with an alternator, but it is not a long-term solution. Knowing the difference between a faulty alternator and a weak battery is critical. According to Nationwide, you can detect a damaged alternator or dead battery in several ways. First, users can check the battery level on the dashboard without starting the car. A faulty battery is unlikely if it still puts out much power. Finally, you should know that your electrical gadgets will try to draw a battery if your alternator fails, leading to faster battery depletion.

How Long Should I Keep My Car Running To Charge The Battery?

You should keep your car running for at least 30 minutes to allow the alternator to charge the battery sufficiently.

When a car battery is in good working order, it can survive two weeks or more before recharging. You should, however, start your automobile every week to recharge your 12-volt battery even if you don’t intend to drive it for some time. If you don’t drive your car too frequently, here are some tips on keeping your battery from going flat. Do not drive if your battery is dead. What should you do? Keep reading to learn the dos and don’ts of automobile battery maintenance.

To keep your automobile in peak condition, fire it up once a week and let it run for at least 15 minutes, regardless of the model. Allow the alternator (or “dyno” in older models) to recharge a battery and keep your engine running smoothly. Turn off the lights if you’re using them because it’s dark, and your car doesn’t automatically do this. Otherwise, you’ll discover that it’s entirely flat when you next attempt to drive—known as a “deep discharge,” lead-acid batteries in automobiles aren’t built to tolerate this discharge. If this happens often, the battery’s lifespan can be reduced by a third.

Does Revving The Engine Charge The Battery?

Yes, revving the engine charges the battery. Whenever the battery is insignificantly discharging, revving your engine will charge it faster. Engineers in the automotive industry create methods that keep the battery charged even while the automobile is in use for long periods, and successively revving the engine is one of them.

When the automobile is idle, lead-acid batteries require just the current delivered by the alternator. This rule does not apply when the battery is at its lowest possible charge level; this rule does not apply. As a result, the battery would be primed to receive a more significant current than when the alternator is running idle. When revving the engine, the alternator boosts the current available to charge the battery. As a result, the alternator speeds up as the engine revs up to charge the battery.

Will a Car Battery Charge While Idling?

Yes, you can charge the car battery while Idling. As long as your engine is running, the battery in your car will begin to charge. Any time there is a mechanical action like crankshaft or turning the alternator. The alternator generates AC power while the engine is on and charges the battery.

The alternator built into your battery allows you to charge it even while your car is Idle. The alternator can provide this with electricity to recharge the car’s battery. In contrast, your car’s engine powers the alternator. Therefore, the alternator will continue charging the battery as long as the engine runs. Between the two of them, it’s a mutually beneficial arrangement. However, it’s a good idea to remember a few things.

At idle, the alternator does not provide the total amount of current. Therefore, the input charge will be less than the charge drained from the battery if you draw a large quantity of power while a car is idling. The computer or ignition may stop working as a result. We may assume from this that the battery recharges slowly when idle, and it would be better to avoid using a lot of electricity when the vehicle is parked.


It is true that all batteries ultimately expire, but keeping a lead-acid battery like the one in your automobile in good operating order is the key to extending its life. Every time your battery dies like this, its overall lifespan is likely to be reduced. Corrosion can be prevented, battery connections can be tightened, and the electrolyte in a non-sealed battery can be kept from leaking, all of which will extend the life of your battery.

Other problems, such as a rapid parasitic drain, may not be preventable, but addressing that problem as soon as it arises will help extend the battery’s life. So, even if you don’t intend to drive for a lengthy period in the winter, a battery tender may assist in keeping your car running smoothly. We hope you have acknowledged everything regarding why your car battery keeps dying.

Robert Aksamit

Robert Aksamit

Robert Aksamit is a mechanical engineer and automotive industry expert. Robert was born in Minnesota and worked in the US automotive industry for 25 years. He is highly regarded for his passion and dedication to continually improving vehicles in response to customer feedback. Robert has a keen eye for sourcing the best vehicle components and materials on the market and is always looking for ways to enhance the user experience. As a writer, Robert covers automotive-related topics. Read more on Robert Aksamit's about page. Contact Robert: robert@promtengine.com

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