Does an ATV Charge Its Own Battery? (Things You Didn’t Know!)

  • By: Kevinsmak
  • Date: September 15, 2022
  • Time to read: 7 min.
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When you’re out on the trails, there’s nothing more frustrating than having your ATV die on you. And if you don’t have a battery charger, it can be an even bigger headache to get it going again.

But what if we told you that your ATV does have a built-in battery charger? It’s true. I’ll tell you about it and how to use it. So read on to learn more.

ATVs use a stator or magneto system to generate electricity to charge the battery. The stator is a set of coils wrapped around a central metal rod. When the engine runs, the stator spins and produces an electrical current. This current is then sent to the battery, which is used to charge it.

How Does an ATV Charge Its Battery?

As we said before, an ATV has a stator that produces electricity to charge the battery. But how does it work?

A shaft (the crankshaft) inside the engine’s crankcase rotates at the same rate as the bike’s RPMs. This shaft rotates more quickly the more throttle you apply.

The engine’s power runs the charging system. At maximum output, the charging mechanism will “rob” your engine of roughly 0.5 horsepower, practically making it a non-issue.

Even at idle, the charging system will take only a very small amount of power from your engine.

The charging system is directly connected to the shaft and has three main components.

  • The stator
  • Rotor
  • Regulator rectifier

The stator is a set of coils wrapped around a central metal rod. When the engine runs, the stator spins and produces an electrical current.

This current is then sent to the battery, which is used to charge it.

The rotor is a magnet that helps create the electrical current in the stator. It is attached to the shaft and spins along with it.

The regulator rectifier is a device that regulates the current from the stator to the battery. It ensures that the battery is not overloaded and damaged by too much current.

There are two most common charging styles:

  • One system style has the rotor mounted directly to the shaft inside the stator. The rotor’s outside is covered in several magnets.
  • Another system variation is where the magnets are connected inside a flywheel that spins on the stator outside.

How These Charging Styles Work

Both systems essentially operate in the same manner: A current will be induced in the coils on the stator when the magnets on the rotor or flywheel rotate past them. This current reverses direction with each rotation, creating an alternating current.

However, because the voltage changes in accordance with the engine speed and is too high at full speed, this current is too unstable to be allowed to enter the bike’s electrical system directly.

Before it can be used to charge the ATV battery, the current must also be changed from alternating (AC) to direct (DC). This is achieved by sending the current through a regulator rectifier.

This is often a small black or metal box with heat fins on the surface for improved heat dissipation from the semiconductors within. The power that comes out of this box is ready to be used by the rest of the bike’s electrical system.

You are using additional electricity when you ride with the headlight and taillight. However, this is not a problem for the charging system because it can produce enough power to charge the battery and run all electrical accessories simultaneously.

When the regulator component of this box malfunctions, too much voltage is fed into the ATV’s electrical system, which is a common failure. Batteries might run out of power, heated grips stop working, and lights burn out.

As soon as you think your regulator has malfunctioned, it’s important to check its output.

Common Problems with ATV Charging System

If your ATV’s battery is not charging, this can be because of the following problems:

Blown Fuse

The fuse is a thin wire that blows when too much current flows through it. Check the fuse to see if it is blown.

Stator Problem

The stator may have failed if there is no power at all coming from the charging system. This can be checked by testing the stator with a multimeter.

If there is no power, then the stator will need to be replaced.

Rotor Problem

The rotor may have failed if the charging system is working, but the battery is not being charged. You can also check this by testing the rotor with a multimeter. If there is no power, replace the rotor.

Regulator Problem

The regulator may have failed if the charging system is working, but the battery is being overcharged. This can be checked by testing the regulator with a multimeter.

If there is too much voltage, then the regulator will need to be replaced.

Bad Battery

A bad battery will not hold a charge and will need to be replaced. This can be caused by several things, such as overcharging, sulfation, or old age.

Sometimes a bad battery can still run a ATV when their starting system and engine are mechanical and not electrical.

How to Prevent Problems with ATV Charging System

The best way to prevent problems with the charging system is to maintain it regularly. This includes cleaning the connections and checking the output of the stator and regulator.

It is also a good idea to replace the battery every few years. If you ride in mud or water, be sure to clean the connections as soon as possible to prevent corrosion.

ATV batteries should be stored in a cool, dry place when not in use. Batteries stored in hot, humid environments will also sulfate and will not hold a charge.

Sulfation can also be prevented by keeping the battery charged when not in use. A battery maintainer is a good investment and will keep the battery charged without overcharging.

Other Alternatives to Charging Your ATV Battery

Sometimes your ATV may not start because of a dead battery; this necessitates charging the battery before you can ride again. However, there are other alternatives that you can use to get your ATV started without having to charge the battery first.

Push Start

Like in any car, you can push start your ATV if it has a manual transmission. This requires another person to help you push the ATV while you hold down the clutch and turn the key.

Once the ATV is moving, let go of the key, and it should start on its own.

Jump Start

You can jump-start your ATV from another vehicle if you have jumper cables. This is done by connecting the dead battery’s positive terminal to the good battery’s positive terminal.

Then, connect the good battery’s negative terminal to the ground on the ATV. Finally, start the vehicle with a good battery and let it run for a few minutes before trying to start your ATV.

Kick Start

If your ATV has a kick start, you can use this to start the engine without using the battery. This is usually only possible on older ATVs because most newer models have electric starters.

To kick start an ATV, push the ATV until it is going fast enough, and then engage the clutch and kick the starter.

ATV Battery FAQs

Does the ATV use all the power to charge the battery?

The charging system only uses as much power as is necessary to keep the battery charged. It does not use all of the power that it produces to charge the battery.

The rest of the power goes to running the bike’s electrical accessories, such as the headlight, taillight, and blinkers.

Why do ATVs use stator systems and not alternators?

All of it comes down to technical difficulties. An alternator requires much air to be blown over it to keep it cool.

However, the air must be generally dry and clean. When installed on an ATV, the alternator will likely be subjected to wet and dirty circumstances that it cannot manage.

Stator systems, on the other hand, are well covered inside the bike’s crankcase and don’t need regular ventilation to remain cool because they’re made to withstand rather high temperatures.

Various combinations of engine coolant, engine oil, and internal fans are used to maintain the stator system working within its permitted temperature range.

How often should I check the charging system?

You should check the charging system every time you ride your ATV. This includes checking the output of the stator and regulator and cleaning the connections.

Final Thoughts

An ATV charging system is a vital part of an ATV, and it is important to understand how it works to prevent problems. You can avoid most issues by regularly maintaining the charging system and replacing the battery every few years.

If your ATV’s battery does die, there are other alternatives that you can use to start the engine. Kindly check out my other article on ATVs, “Are ATVs Automatic or Manual? (3 Types of ATV Transmissions)

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