Car Battery Won’t Charge (Causes & Solutions)

Are you in a situation where your car battery won’t charge, and you want to know why and how to fix it? If yes, you are on the right page.

No matter how important the car engine is, the car battery is responsible for routing voltage to your starter, which turns the engine over.

In addition, the battery supplies electricity that powers all lights, navigation systems and audio, computers, and other electrical-dependent parts. If the car battery doesn’t hold a charge, the car will not be able to move.

Throughout the life of the car battery, it’ll cycle through numerous discharges and charges. Starting your car is the battery’s main purpose, but it’s equally used for providing accessories with extra power when your engine goes off. You must recharge the battery while your engine runs, so it’ll be ready for your next start.

This article provides you with solutions to problems with your car battery. Kindly read through to be more enlightened on why your car battery won’t charge and how to fix it.

Another common reason for your car’s battery not charging could be a problem with the alternator.

When the car key in its ignition is turned, the battery powers the starter motor, and the engine starts. It equally provides petrol cars spark plugs, with their initial spark. It powers the heater glow plug, with a temperature below zero in most diesel cars.

But immediately after the engine starts, the alternator should recharge the battery.

When an engine begins to run, a belt converting mechanic power to electrical power drives the alternator. The battery is charged by this power and provides all other parts the necessary power to run, like interior lights, radio, headlights, and other accessories.

The battery light in the car means your battery is not charging like it’s supposed to or not charging entirely. The little light has a battery shape and comes on for a few seconds when you start your car, but if it turns on when you’re already driving or remains on, there’s a problem.

Also Read: Battery Discharge Warning (Meaning, Causes & Fix)

Here are some reasons why the car battery is not charging:

1. Faulty Battery

Car Battery Won't Charge

This is a significant reason why a car’s battery refuses to charge. The obvious signs that the battery is worn out and too old are cracking and corrosion. If the battery is at least four years, you must replace it.

A car with a younger battery that hasn’t been started for days/weeks can equally refuse to charge. When too damaged or old, batteries can bloat, become corroded, have battery acid leaks, or develop cracks.

Too much corrosion on batteries reduces their charging ability and electrical connectivity. Sulfating can be suffered by older batteries, where there’s damage to the battery cell’s internal plates.

All lead-acid batteries can sulfate, though it can be reversed at early stages. Consider battery replacement in this case.

2. Faulty Alternator

One of the first reasons your battery isn’t charging is the possibility that the alternator is bad. This alternator is responsible for converting the engine spins into power that goes back into the battery.

When an alternator and car work properly, the battery is being charged by the alternator as you’re driving, giving it enough power to start your car when next you want it to. When the alternator goes bad, it doesn’t provide a charge to your battery, meaning the battery won’t be charging.

Simple situations, like bad connections, could cause the alternator not to charge the battery. If that’s the case, reconnecting the wires will solve the problem. The alternator and battery can be disconnected when wires go bad or there are vibrations while driving.

If they aren’t disconnected, then something else must have gone wrong. You could run an alternator test using an automotive multimeter to find out if it’s giving voltage at all.

Also Read: Can a Car Battery Be Too Dead to Jump Start?

3. Damaged Drive Belt

A rubber drive belt (serpentine belt) drives the alternator. Alternator speed changes with the engine speed. The belt stretches sometimes or becomes frayed, mostly in older cars.

The belt then loses its grip on the alternator’s pulley, making it slip. A belt slipping can’t keep up with the powers the car needs because it won’t drive an alternator as it should. Pulleys connect all the belts to the engine.

The pulleys are slightly tough and don’t have a limited lifespan. When you notice a belt slipping or noise from the pulley, they might need changing.

4. Blown Fuse – Check The Fuse Box

Sometimes just one simple fuse could stop the starting of your car. Other times, the fuses just blow without reason, especially in older cars. They become worn out and brittle with age, and cold engine starts might be so much more than what they can handle.

For starters, check the starter motor and alternator fuse. Then, check your user manual again to get information concerning the fuse box and other individual fuse locations. If they’re all okay, then you have to dive deeper.

You can decide to hire a good auto electrician or mechanic now because car electrics could be complicated.

5. Power Drain On The Battery

Car accessories, such as Bluetooth kits or interior lighting, generally shut down when the car engine goes off. When these accessories don’t power down as they should, they can all drain your battery.

Some components might need live connections for specific settings to be retained, and they can create abnormal draws on the car battery, eventually causing its failure.

6. Faulty ECU

Most modern cars have onboard computers called Engine Control Units (ECU) that manage electrical systems in your car. A faulty ECU can cause problems with the charging system.

An ECU error comes with signs like an engine check light or engine stalling. When you suspect that your ECU is bad, have it immediately diagnosed by a mechanic.

Also Read: How To Charge A Car Battery Without A Charger (6 Best Ways)

What Should I Do When My Car Battery Won’t Charge?

Car Battery Won't Charge

First of all, a car battery wouldn’t just suddenly stop charging.

The process is gradual, and there’re plenty of factors for you to consider, like if the alternator doesn’t supply charges enough to charge your battery, or the alternator belt (serpentine belt) is either being loose or going off completely, or the battery is not capable of holding a charge for long periods because of age, or the car accessories including Bluetooth kits or interior lighting, that’s supposed to shut down with the engine, don’t.

When the accessories don’t power down as they should, they’re capable of draining the battery. In rare cases, electrical connections can come undone, probably due to excessive vibrations or poor connections caused by rust.

Try some of these steps if you find out your Car Battery Won’t Charge:

  • Firstly, try turning the headlights on. If they turn on as they should, your problem may be poor wiring or a bad starter, and not a battery problem. If the headlight doesn’t come on or becomes dimmer than they normally are, the battery is more likely to be the problem.
  • Test the battery voltage using a voltmeter; red lead should be connected to the positive terminal, and black lead should be connected to the negative terminal. You will hopefully get over 12.6 volts reading, showing that your battery is fully charged – if not, then there is a problem with your battery, as it charges poorly.
  • Also test the voltage that comes from the alternator using a multimeter. On most vehicles, it should read between fourteen and fifteen volts. If not, then there’s probably not enough power to run the vehicle and charge its battery. If you suspect it’s the alternator, inspect it visually for lost wires or damages. You might need an expert to remove and test it because it might be difficult to reach.
  • Sometimes, you have to check out the battery’s condition. Find out if it’s worn out or corroded, find out its age, and if it is more than four years; the best and simple solution is to replace the battery.
  • Another thing to be considered is whether your problem is the alternator. When you spot fraying or cracking on the cables of the alternator, the sign is obvious that there’s something off. And when the car is jump-started, only for you to experience stalling engine, and a battery that loses charge quickly, it suggests an alternator problem.

You might still want an expert’s opinion, even when you’ve found the problem. Buying a new alternator when the battery is the problem or the other way around will be highly frustrating because you’ll spend more than you’re supposed to.

Instead, take your car to a center for car cares in your locality for inspection so that you can know the root of the true problem.

Also Read: Service Battery Charging System (Causes & Fix)

Frequently Asked Questions – Car Battery Won’t Charge

What drains a car battery overnight?

It could result from different factors, including leaving cabin lights, glove-box lights, or headlights on overnight. A new battery’s poor installation, bad wiring, and defective fuses can also cause a parasitic drain.

Can a completely dead battery be recharged?

No battery, dead or healthy, can charge on its own. An external source of power is always required for the battery to charge. Once a battery dies, the alternator completely fails to recharge it. If the vehicle stops, you likely have problems with your alternator. Checking the car’s interior light is another way you can simply test it. Your battery is being charged by an alternator when your car runs. If the dashboard and interior lights shine brightly and then starts fading slowly, it shows you have an alternator problem.

Can a battery be too dead to jump?

No, car batteries can never be “too dead” to at least jump-start. When the jump-start refuses to work, it indicates that your battery is dead and needs replacement or a faulty alternator.

How long does charging a dead car battery with jumper cables take?

To charge the battery fully, you’ll need to allow the other car to charge it for about 30 to 45 minutes. Because the car will run off your battery, once it is charged up, it’ll not be able to make it 15 miles.

How much do car batteries cost?

A typical car battery costs between fifty to one hundred and twenty dollars, although some special batteries can cost more, like ninety to two hundred dollars. We have more than forty kinds of batteries, and different factors affect their cost.

How much do alternators usually cost?

The average cost of an alternator is between $100 and $350; this depends on the model and make. Most cars average, cost between $350 to $400 for every work to be done to replace an alternator if no part needs replacement. Add another twenty to fifty dollars to the bill if the process includes a serpentine belt.

Conclusions – Car Battery Won’t Charge

As you already know, a few reasons are responsible for causing a car battery not to charge. You might have a belt that’s loose or a faulty alternator in the car. Your car battery itself might be bad.

Worn-out and old batteries are another factor, or the battery might have damages that we can’t see. If you’ve recharged the battery a couple of times, then it probably won’t be able to recharge again.

Now you understand better why your car battery will not charge, and you should be capable of troubleshooting it for situations at hand concerning you and your current situation.

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