Car battery keeps dying but Alternator is good

The battery is supposed to be the brain of a car. Without a battery, the engine of your car is just a toy. A battery provides all the necessary power for the car to function properly. 

But if your battery continues to die every now and then, it seems like a pain in the ass, right? You checked the alternator, but it’s completely fine. So the question can pop into your mind why the car battery keeps dying but the alternator is good? 

Well, we found some possible answers to your question. Stay with us to the end as we’re going to explain everything.

What are the Possible reasons behind the dead battery? 

If your new car battery is constantly dying, it’s not necessary you have a faulty alternator. Then what does it mean if my car battery keeps dying? There may be some other issues behind a dead car battery. Likewise: 

Corroded battery

If your battery continues to die, this indicates that the alternator is not charging it properly. If you have a new alternator, then the problem could be something with the battery connection. 

Corrosion generates resistance, which prevents the battery from receiving a complete charge. You may see some white or green object on the battery terminal. 

Corrosion can happen on both the positive terminal as well as the negative terminal. To get rid of corrosion, you may use some baking soda or white vinegar. Clean the battery post and cables free from corrosion. It will prologue the life of the battery.

Extreme temperatures

Extreme temperatures can cause your car battery some serious damage. Voltage regulators and other charging equipment might fail if the temperature is too high. This might lead to overcharging of your battery. Overcharging leads to battery death on a regular basis. 

Likewise, freezing temperature can also cause some serious battery problems. Your car battery won’t work even if you have a new alternator if you store it in extreme temperatures.

Faulty electrical wiring

Faulty wiring can also lead you to a dead car battery. Wiring problems are hard to find out, and repairing is more challenging. But here are some signs from which you can tell that there’s a problem with the wiring: the first one is damage to the outer wiring sleeve. To preserve wires from corroding and from touching metal, this insulation is essential.

The second one is a rusty battery cable or battery terminal. The third one is internally damaged cables caused by bent wires. They are harder to find, though. If you think there has been some faulty wiring, you need to check the wire from the battery to the fuse panel is okay or not. Additionally, check the battery cable to the ignition switch from the battery.

Depleted car battery

It’s possible that your car’s battery will die if it has been parked for a long time or if you don’t drive it regularly. When the car is not in use, the battery loses its charge. The voltage or charge gradually diminishes over time.

Furthermore, if you just drive the car once a week, the alternator will be unable to perform its functions. The charge is greatly reduced when the automobile engine is started, and it takes time to regain the full amount of power. The shorter travels will entirely deplete the battery.

Ground Connection Issues

There are some grounds when your battery can act as a dead battery. But it’s not really dead. The reason behind this strange behavior of the battery is a poor ground connection. The ground connection is in charge of completing the circuit between the battery and the starter motor by connecting the two together. 

If this connection is not satisfactory, you will have difficulty starting the vehicle. It will then show some symptoms that are similar to those of a dead car battery.

Parasitic battery drain

If your battery continues to die despite the fact that your charging mechanism is operating normally, you may have a parasitic drain. A parasitic drain occurs when something draws power or voltage from the battery while you keep the ignition switched off.

Sometimes, this type of battery problem occurs due to a short circuit. If you keep it unfixed, the electrical system like interior lights and dashboard lights keep draining power from the battery. It will lead to you a depleted battery, and the car won’t start at all.

Why is my car’s battery constantly dying while driving?

If your battery continues to die during a drive, it may not be a compulsorily bad alternator or bad battery. When you start the vehicle, the starting motor gets a boost from your battery. 

After that, the battery is not a command at all. The charging system takes over the control. Starting the motor simply indicates that you have a perfectly working battery. So it might be either a faulty alternator or any loose connection.

If you have checked the alternator thoroughly and can not see any defect, then you should check if the alternator belt is tightened up or not. The loosened belt may cause this kind of problem. Simply tightening up the alternator will fix this problem.


A car battery powers up your car’s electric components like dash lights, headlights, interior lights, radio, etc. Even a new battery or good battery can keep dying with a good working alternator. 

An alternator is not always to blame for a dead car battery. There are some more reasons. If your car battery keeps dying after a few days, you should go through the troubleshooting guide mentioned above.


  1. What is draining my car battery when it’s off?

Even while your car isn’t running, your battery powers the clock, radio, and alarm. These things shouldn’t harm your battery. Interior lighting, door lights, and even defective fuse can deplete a car’s battery when it’s off.

  1. Can a bad battery affect the alternator?

An alternator can destroy a battery, but not the other way around. The car battery can not provide electricity for long durations. Therefore both electrical components must be working properly.

  1. Will a new alternator charge a dead battery?

Alternators help to maintain the battery voltage or charge. But if a battery is dead because of the charge and discharge process the alternator can not charge it.

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