Why Is My Motorcycle Battery Not Charging?

Most motorcycle riders have experienced the sinking feeling of walking out to their motorcycle, prepared to take it for a ride, only to find that their battery is dead. If your motorcycle battery won’t charge, it can be frustrating, not to mention a major inconvenience. 

Imagine being on a road trip and your bike suddenly won’t start because the battery is dead. And you start wondering why is my motorcycle battery not charging. There are a few things that could be the potential culprit to this problem. It could be a loose connection, a damaged alternator, a faulty rectifier, a faulty voltage regulator, damaged stator wires, or any other reason.

In this blog post, we’ll explore all of the potential reasons why your motorcycle battery might not be charging. We’ll also explore what you can do to fix the issue, so let’s get started.

Why Is My Motorcycle Battery Not Charging? 10 Reasons

Taking care of your motorcycle’s battery and charging system is imperative for keeping your bike running smoothly. By regularly inspecting and maintaining these components, you can prevent potential problems like a dead battery or a non-charging one. And if you do run into any issues, following these steps can help you troubleshoot and resolve them.

1. Check the Battery Terminals

The first thing you should do if your motorcycle battery won’t charge is to check the terminals for corrosion. Over time, battery acid can corrode the terminals, preventing electrical current from flowing freely between the battery and the rest of the motorcycle.

If you see any corrosion on the terminals, clean it off with a wire brush or a terminal cleaning tool. Once the terminals are clean, try charging the battery again.

2. Sulfation

The most common reason is sulfation, which occurs when the lead sulfate crystals on the battery’s lead plates grow too large. This can happen if the battery is left unused for too long. Additionally, it can happen if it’s repeatedly overcharged, undercharged, or simply letting the battery sit for too long without being used. Sulfation can also be caused by excessive heat or vibration.

If your battery is sulfated, you’ll need to have it replaced. But if the problem is something else, like a loose connection, you may be able to fix it yourself.

3. The Charging System

If cleaning the terminals doesn’t solve the problem, then it’s time to check the charging system. The charging system includes the alternator, regulator/rectifier, and related wiring.

A problem with any one of these components can prevent your battery from charging properly. To test the charging system, you will need a multimeter.

Step 1: First, turn on the ignition and lights (headlight, taillight, etc.) to drain any power from the battery.

Step 2: Then disconnect the negative (-) terminal from the battery and connect one of the leads from your multi-meter to this terminal.

Step 3: Touch the other lead from your multi-meter to a metal part of the motorcycle frame (make sure that this part of the frame is not connected to any electrical components).

Step 4: You should see a reading of 12 volts or more on your meter. If you don’t see this reading, then there is a problem with your charging system. You will need to take your motorcycle to a mechanic for further diagnosis and repairs.

4. Check for loose wires

Another reason why your motorcycle battery might not be charging could be loose or damaged wires somewhere in your motorcycle’s electrical system. To check for loose wires, visually inspect all of the wiring in your motorcycle’s charging system (alternator, regulator/rectifier, etc.). Look for frayed or broken wires, and ensure that all connections are tight and secure. If you find any frayed or damaged wires, repair or replace them as necessary and then try charging your battery again.

5. Bad Alternator or Rectifier

If all the connections are secure and there are no obvious problems with the wiring, then your alternator or rectifier may be faulty. The only way to tell for sure is to have a mechanic check it with a multimeter.

In some cases, you may need to replace the entire charging system if the alternator or rectifier is malfunctioning. However, it’s worth checking to make sure that there aren’t any other issues first before replacing the entire system.

6. Dead or Weak Battery

It’s also possible that the problem is with the battery itself. A dead battery, for example, will not charge no matter what you do. And a weak or old battery may not hold a charge for very long, even if it does seem to be charging properly.

In this case, you will need to replace the battery with a freshly charged one. It’s always a smart idea to check the condition of your battery regularly and replace it before it completely dies. This can prevent damage to other parts of the electrical system.

7. Battery Age

Another possibility is that your battery may simply be too old and can no longer hold a charge. This is especially common if you haven’t been regularly maintaining and charging your battery, or if it’s been several years since you last replaced it. In this case, the most effective solution is to replace the battery with a replacement one.

Keeping your motorcycle battery properly charged and maintained can prevent these issues from happening in the first place. Regularly check for corrosion on the terminals and make sure that the charging system is functioning properly. And always remember to fully power up your battery after each ride. By taking care of your battery, you’ll ensure that it will last for many years to come.

8. Faulty electrical components

You might have a problem with one of your motorcycle’s electrical components. This could include faulty headlights or taillights, a short in the wiring, or any other component that is draining power from the battery.

If you suspect this may be the case, try disconnecting each electrical component one by one to see if the battery begins charging properly. If that does not work, your motorcycle needs to be diagnosed and repaired by a mechanic.

9. Incorrect charging

It’s also critical to make sure that you are charging your battery correctly. This means using the correct charger for your battery type and following all instructions for proper charging. Incorrectly charging the battery can lead to damage and prevent it from holding a charge properly.

10. Extreme Temperatures

Extreme temperatures can also affect the ability of your battery to hold a charge. It’s critical to store your motorcycle in a cool, dry place and avoid leaving it out in the hot sun for extended periods. This can help prolong the life of your battery.

What are the signs of a dying battery?

  • The car takes longer to start or doesn’t start at all Diminished power when driving and loss of electrical components (ex. headlights, radio).
  • Swelling or bloating of the battery case- A rotten egg or sulfur smell coming from the battery
  • The battery is old (typically lasts around 2-5 years)It is critical to regularly check the battery and electrical system of your car to prevent any unexpected breakdowns.

If you notice any of these signs, it is time to replace your battery. It is also a smart idea to have a backup or spare car battery on hand in case of emergency.

Is it a problem if my motorcycle battery dies?

Yes, it can be a problem if your motorcycle battery dies. This is because it will prevent your vehicle from starting and you may not have access to an alternate means of transportation. It is incredibly vital to regularly check and maintain your battery to avoid this issue.

It also depends on the circumstances. If you are in a remote area without access to help or a spare battery, it could be a problem. However, if you are near a motorcycle shop or have roadside assistance, it may not be as big of an issue.

If your battery does die, you will likely need to replace it or jumpstart it with another vehicle or external device. It is also helpful to have a plan in place for emergencies such as this.

Overall, it is wise to regularly maintain your battery and have a plan in case it does die to prevent any issues or inconveniences on the road.

How to prevent the battery from dying?

Some ways to prevent a battery from dying include:

  • Keeping the device charged and not letting it run down to low levels 
  • Avoiding extreme temperatures, both hot and cold 
  • Unplugging devices when they are fully charged
  • Replacing old or worn-out batteries
  • Using power-saving modes on devices
  • It is also imperative to properly dispose of batteries and not just throw them away, as they can be harmful to the environment.

Following these tips can help prolong the life of your battery and save you from having to replace it frequently.


If your motorcycle battery won’t charge, don’t panic! As we discussed, there are several things you can do to troubleshoot and fix the problem yourself.

If you still can’t get your battery to charge after trying all of these things, then take your motorcycle to a qualified mechanic for further diagnosis and repairs.

I hope this helps! Thanks for reading!

About David Riedel

I am David Riedel founder of Bikerwhizz, I'm a technician at Keystone Harley Davidson with more than 10 years of industry experience. I’m here to help you solve motorbike problems, customizations, tweaks, and easy fixes to enjoy your rides more.

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