Battery Light on but Alternator Is Charging – What’s the Problem

Modern car’s charging system contains a battery, an alternator, and an electronic control unit (ECU). Older cars also had a voltage regulator. Battery is an important part that provides the essential power to the car on the road to run. Besides, the alternator turns engine mechanical energy to electrical energy to charge the battery.

One of the problems, which many drivers face, is the battery light on but the alternator is charging. Although it seems simple, the actuality is more difficult. The problem comes from a battery voltage, bad alternator, corrosion or loose electric connection.

In this article, we’ll discuss all about figuring out the reason for your battery lights on while the alternator is charging. Our hardcore information gives a guide to detect and solve your car’s situations. Hopefully, you can easily trace what’s the problem and solve the problem. 

Battery Light on but Alternator Is Charging- What’s the Reason:

battery light on but alternator is charging
source: https://www.pistonheads.com/

When you start the car, the battery light stays on for a few times, so no need to worry. Few moments later, the light turns off normally. But,  if the battery light stays on when the alternator is charging, then pay attention to it. You notice some signs such as battery voltage, corrosion on the battery or loose clamps. Let’s take a glance to see where the problem is hidden.

Battery Voltage:

Usually, a fully charged battery should be around 12.6 volts or more. You can use a digital multimeter to check the voltage of your car’s battery. But, when the alternator is charging, the voltage of the battery should be 13.5-14.5 volts. Once the battery light is on with the voltage above 13 volts, there’s something wrong with the alternator.

Bad Alternator:

There’s a chance of a bad alternator when the battery light remains on with a voltage higher than 13 volts. First of all, confirm the alternator was bad. Hopefully, it takes only a few minutes, and you don’t need to remove the alternator from your car. You’ll only need a digital multimeter for the tests. You can use this digital multimeter to check the alternator. Alternator voltage should be 13.8-14.2 volts. You have to install a new alternator when the voltage is lower than normal. Here are some bestseller alternator you can install in your vehicle.

Corrosion Problem:

If you see any sign of corrosion, it can be the cause of why your car’s battery light is still on. The presence of a greenish or white substance on the top of the battery terminal is a sign of corrosion. Hopefully, you can easily clean the corrosion from the car’s battery. You just need a teaspoon of baking soda and a glass of water to prepare the solution. Then use a home toothbrush or bristle brush to scrub the solution on the corroded areas. 

Electrical Connection:

You should also check all the connectors and similarly check the fuses. The battery light stays on for the weak connection between the cables. Cables and fuses work to connect between the battery, alternator and the ECU. 

Again, make sure the clamps tighten to the battery terminals. If you find the clamps are loose, then use a Clamp Tightening Wrench to tighten them.

Symptoms You Must Not Ignore:

Symptoms You Must Not Ignore
Source: https://www.thirdgen.org/

Although these are the main reasons for the battery light on while the alternator is charging, you should know other signs. These signs indicate important issues including the two parts.

Bad Battery Signs:

  • Inconsistent interior light, headlights.
  • Corroded or loose connection.
  • Visible corrosion on the top.
  • Lights on but the car can’t start.

Bad Alternator Signs:

  • Warning light on indicator dashboard.
  • Flickering or dim headlights.
  • Face problems to start regularly.
  • Smells or sounds from electrical accessories.

Appliances You Must Needs:

  • Digital Multimeter: You can use a digital multimeter to check the alternator and voltage of your car’s battery. We recommend Klein Tools Or WeePro Digital Multimeter.
  • Baking Soda: You also need some water and baking soda to prepare a corrosion cleaning solution. We suggested ARM & HAMMER Pure Baking Soda for corrosion cleaning.
  • Toothbrush or Bristle Brush: These two are household tools that are used in daily life. If you don’t have a new one, you can buy a toothbrush or bristle brush to scrub the solution on the corroded areas.
  • Clamp Tightening Wrench: You have to use a small clamp tightening wrench to tighten the clamps. If you don’t have one, you can buy the Clamp Tightening Wrench to tighten them.
  • New Alternator- The Final Solution: You don’t have any other options instead of installing a new one when anything goes bad to the alternator, Here are some bestseller alternators you can choose to install according to your vehicle’s.

Conclusion:

The battery is one of the most important parts that provide the power to run on the road. Likewise, the alternator turns engine mechanical energy to electrical energy to charge the battery. The battery light on but the alternator is charging is a common problem that many drivers can face. The problem comes from a battery voltage, bad alternator, corrosion, or loose electric connection.

Although, it looks simple but the reality is more difficult, so you must have to detect and solve the problem. Hopefully, our problem solving article gives you a guide to detect and solve your car’s problems. Now, you can detect the peak of the problem and solve the situation. 

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