How does a Motorcycle Alternator Work?

How Does a Motorcycle Alternator Work?

I was checking my motorcycle battery health and wondering how a single device can charge the motorcycle battery. And deep down, I thought, why shouldn’t I write a post about how does a motorcycle alternator works?

The motorcycle alternator set consists of a magnetic flywheel. When you ride the motorcycle, the flywheel rotates around the immobile alternator, consisting of a magnet thus converting mechanical energy to electrical energy through magnetic energy. 

Let’s look at what it means for you and what you can do about it. In this post, I’ll cover the proper functioning of alternators and some signs of faulty alternators. 

How Does a Motorcycle Alternator Works: 

An alternator or stator is a simple device that converts mechanical energy to electrical energy with the help of magnetic energy. The whole set of alternators consist of a flywheel which also has a magnet on it. 

When you ride a motorcycle, the flywheel rotates around the immobile alternator, producing magnetic energy. Thus the equation would be: 

Mechanical energy (produced when you ride a motorcycle) → Magnetic energy. 

In the influence of magnetic energy, the electrical charge produces. This electrical charge is of AC, which is of no use. Wait, what? AC (Alternate Current) would be of no use? 

Magnetic energy (produced by the influence of mechanical energy) → Electrical energy.

The battery can’t store the AC current, so the manufacturer fitted the device called a rectifier. The rectifier converts the AC current to DC current so that the battery can charge enough. 

The alternator’s functioning depends upon how much and at what speed you ride the motorcycle. High motorcycle speed can produce a high voltage electrical charge which can fuse the battery. 

Thus manufacturers fitted the device called regulator to reduce the electrical current voltage in the range of 14.5~15 VDC. You can find the set of regulators and rectifiers a little away from the alternator. 

What’s the Role of Battery? 

You must be wondering what the battery’s role is when the alternator/ stator is the main component that generates charges. Then why do you need a battery for your motorcycle? 

Try to understand one thing: 

Your motorcycle alternator only works when your motorcycle is in motion. And to bring the motorbike into motion, you need a battery since the battery stores charge, which you need to ignite the motorbike engine. Without a battery, your motorbike wouldn’t generate enough power to ignite the engine. 

So to run your motorcycle effectively, you need a good battery as well as a good stator. 

Signs of a Faulty Alternator? 

Generally, the alternator doesn’t cause any signs if it’s malfunctioned but causes some silent symptoms through which you can predict whether the alternator has malfunctioned or not.

Signs of Faulty Alternator
Sluggish Light. 
High RPM problems. 
Whining sound. 

Sluggish Light: 

Sluggish light is one of the most prominent signs that can be caused when your alternator malfunctions. 

Your motorbike battery starts draining even if you ride your motorcycle regularly; even sometimes, you’re going to find difficulty in starting the motorbike. 

You can’t rely only on this sign as it is also caused when your battery malfunctions. It would be best to take your motorbike to a technician if you find this sign. 

High RPM Problem: 

A faulty alternator not only causes your battery to discharge but also interfaces the common working mechanism of your motorbike. 

There’s a need for more energy at high RPM, which a faulty alternator can’t produce, so you’re likely to face some challenges when taking your motorbike at high RPM. 

Whining Sound: 

The third silent sign of a faulty alternator is the whining sound you keep hearing while starting your motorcycle. You may especially hear this sound if you aren’t turning your throttle.

How to Maintain a Motorcycle Alternator? 

Undoubtedly an alternator is the heart of your vehicle, so it’s better to maintain your motorcycle alternator regularly. 

Here’re some tips through which you can maintain a motorcycle alternator.

How to Maintain a Motorcycle Alternator?
Wiring: Swap old copper wires (if they’re burned) with good quality, minty fresh copper wires.
Cleaning It would be best if you check your engine regularly and wipe any dust and debris stuck in the alternator.
Test problem: If you find your motorcycle light starts dimming slowly, it would be best to give at least a check to your motorcycle alternator.
Shift to new alternator: Swapping old alternator with new; otherwise, your motorbike will start using battery power.
Don’t install unnecessary devices: Installing additional devices more than your motorbike potential may harm your motorbike electrical system in the long run. 

Wiring: 

The motorcycle alternator has copper wiring in it, and it might burn because of heat. 

I recommend swapping old copper wires with good quality, minty fresh copper wires. Doing this will surely add some life to your alternator. 

However, if alternator copper wires are totally burned off, then ask your technician for a better solution. 

Temperature: 

Any engine can only work best if it doesn’t overheat, and it’s also true for your alternator. Alternators sometimes overheat because of dust and debris. 

It would be best to check your engine regularly and wipe any dust and debris stuck in the alternator. Avoid using any petroleum-based product for cleaning the alternator. 

Test Problems: 

If you find your motorcycle light starts dimming slowly, it would be best to give at least a check to your motorcycle alternator. 

It’s not always necessary that there’s a problem with your alternator. There could be a problem with your battery or wiring, and checking the alternator, in this case, may avoid a big problem.

Change Old Alternator: 

If there’s any problem with your alternator, it would be best to shift to a new alternator. Otherwise, your motorbike will start using battery power. And this might cause your motorbike battery to die. 

Avoid Installing Unnecessary Devices: 

Our motorbikes are starting to get more intelligent day by day, thanks to smart devices. But are installing additional devices good for your motorbike? 

No, installing additional devices more than your motorbike potential may harm your motorbike electrical system in the long run. 

And that’s why I would always recommend you checking the power guide of your motorcycle and see how much output your motorcycle supports. 

Can You Ride a Motorbike Without a Stator? 

So far you understand the working of the stator, now the question arises, can you ride a motorbike without a stator. 

Stator helps to generate an electric charge when riding. In simpler words, it helps to convert mechanical into electrical energy. Without a stator, your motorbike won’t get any electrical charge and you’ll need to carry tens of motorbike batteries with you. In simpler words, you can’t ride a motorbike with a stator.  

You can ride your motorbike without a stator. But the only thing you need is extra batteries which you need to replace after some time in your riding journey.  

And if your motorbikes have some extra accessories installed, it would be better for you to carry more than ten motorbike batteries. 

Yes, this is how your life would happen if you ride your motorbike without an alternator. And to tackle these challenges, you must have to ride a motorbike with an installed stator.

How Long Would it Take to Charge the Battery? 

As mentioned above, the stator converts mechanical energy to electrical energy. But have you wondered how long it would take the stator to charge your motorbike battery?

Generally, the motorcycle battery charges best at 13.5-14.5 V, which means you need to ride your motorcycle for at least 3 hours to charge the battery completely. And in this sense, the charging speed will increase as you increase the motorbike speed. 

You can further decrease the charging time by switching off the additional accessories you installed on your motorbike. Additionally, the smaller the battery size, the faster it would charge. 

Also read, why and how motorbike rectifier gets hot? Read here.

Frequently Asked Questions:

What’s the main principle behind the working of a motorbike alternator?

Converting mechanical energy into electrical energy is the main principle behind the working of a motorbike alternator.

What is the role of the battery?

Battery stores charge, which you need to ignite the motorbike engine. Without a battery, your motorbike wouldn’t generate enough power to ignite the engine. 

What is the main symptom of a faulty alternator?

Sluggish light is the most common sign of faulty electrical system or alternator?

In how much time the alternator would charge your motorbike battery?

Generally, the motorcycle battery charges best at 13.5-14.5 V, which means you need to ride your motorcycle for at least 3 hours to charge the battery completely. 

Can you ride a motorbike without a stator or alternator?

No, you can’t even cross 1 mile without a stator or alternator.

Final Verdict: 

How does a motorcycle alternator work? The motorcycle alternator set consists of a magnetic flywheel. When you ride the motorcycle, the flywheel rotates around the immobile alternator, consisting of a magnet.

Thus converting mechanical energy to electrical energy through magnetic energy. 

I recommend checking wiring, temperature, and swapping to a new alternator if you face sluggish light problems and whining sounds. 

Here are Some of My Favorite Riding Gears: 

Thank you for reading this article. I hope you found it helpful as you build your riding journey successfully. 


Here are some riding gears I use as a rider that I hope you’ll also find helpful.

These are affiliate links, so I’ll earn a commission if you decide to use any of them. But in all honesty, these are the same riding gears that I use and recommend to everyone, even my own family.


Motorbike Riding Pants:


For getting started, I like Scorpion EXO Covert Jeans for men (check the latest price on Amazon.com) and Indigo Protective Riding Jeans for women (check the latest price on Tobacco Motorwear).

These riding pants are comfortable so you can use these pants in summer, and these pants have a lot of space for using knee guards. 


Motorbike Riding Helmet:


Throughout my riding life, I used several helmets, and almost all helmets protect your head well. Still, I personally prefer YM- 929 Yema helmets as it comes with Bluetooth and aerodynamic ABS shells (check the latest price on Amazon.com).


And suppose you want an eye-appealing and yet effective helmet. In that case, you can go with Icon Airform Sacrosanct Helmet (check the latest price on Revzilla). 


Motorbike Riding Jacket:


Jackets are crucial to protect your upper body. Honestly, every rider has a dream to have an affordable yet best riding jacket. And that’s why I personally recommend the Alpinestars T faster motorbike jacket because of the protection and comfort it offers (check the latest price on Amazon.com). 


Motorbike Riding Gloves:


Almost all riding gloves perform well by protecting your hands from sunburn and cool nights. And if you’re a serious rider, then you should go with Alpinestars SMX-1 Air v2 Glove, which is lightweight and offers you excellent protection. (check the latest price on Revzilla).