Skip to content
motorbeast logo
  • Autos
  • Audio
  • Bikes
  • Batteries
  • Detailing
  • Oils
  • Parts
  • Questions
  • Roof Boxes
  • Scanners

Does A Motorcycle Battery Charge While Idling?

Written BySteve Riley Updated on28/05/2022

‘Jump start it, let it idle for a couple of minutes and you will be good…

‘Jump start it, let it idle for a couple of minutes and you will be good to go.’ That is the advice you get from most people when your motorcycle battery dies. But does a motorcycle battery charge while idling? Read on to find out if it does and if it doesn’t why not.

Table of Contents
  • How a Motorcycle Charging System Works
    • Battery
    • Alternator
    • Rectifier/Regulator
  • Key Concepts
  • Minimum RPMs for Charging
  • So Does A Motorcycle Battery Charge While Idling?
    • Assumptions Made
    • What If The Battery Dies?
  • Conclusion

Every biker has had the unpleasant experience of a dead battery. When this happens, the engine won’t start and none of the bike’s electrical components works.

The standard advice you get is to use jump cables to jump start the engine and then leave it running for a while to let the battery recharge. Jump starting does get the engine running but does idling help? Does a motorcycle battery charge while idling?

In this article, we answer this question with a clear explanation on why we can conclude that a motorcycle battery does not charge while idling.

How a Motorcycle Charging System Works

The charging system in a motorcycle is made up of 3 main components. These are the battery, an alternator and a rectifier, also called a regulator.

Battery

The battery is the primary source of electric current. It stores it waiting until it is required to start the engine .When the starter button is pressed, stored current flows from the battery to the starter motor, fuel system and ignition system to start the engine.

Although it takes a second or two to do this, it draws a significant amount of current from the battery and there is need to replenish it. Drain may be increased if electrical accessories such as lights are on.

Alternator

The role of the battery is merely to provide the current required to start the engine. Once it starts, it is the alternator which generates electricity to power the engine and other electrical components.

It also recharges the battery to replenish what was spent to start the engine, ensuring it is ready and able for the next time the engine needs to be started.

Rectifier/Regulator

The alternator produces current but it is not in a form which can be utilized. It produces Alternating Current (AC) which must be converted into Direct Current (DC). This is the role of the rectifier. Its regulatory role is to control the current being channeled to electrical components of the motorcycle.

Key Concepts

To gain a clear understanding of a motorcycle’s battery charging process, let’s look at two key concepts. These are idling and RPMs.

Idling:  This refers to the state when the engine is running but the motorcycle is not in motion. You would find yourself idling when waiting in traffic or warming up the engine on a cold day.

Idle speed is the rotational speed the engine is running at when it is on idle.

RPMs: (Rotations of Revolutions per Minute.) This refers to the rotational speed of the engine’s crank shaft which powers the rear wheel through the gearbox.

As the crankshaft rotates, the gears move and this translates to speed for the engine.  The faster the crank shaft rotates, the higher the RPMS and the faster the bike moves. As RPMs increase, fuel consumption of the engine increases.

Minimum RPMs for Charging

As mentioned, the alternator serves to charge the battery to replenish whatever has been spent to start the engine. However, there is a minimum number of RPMS at which the alternator can kick in and start charging the battery.  Below this, the alternator does not do its job even if the engine is running.

With this in mind, the key question then is ‘how many RPMS are required to get the alternator working?’  There is no standard number because it depends on the type of alternator. However, a standard alternator starts producing charging current at 2000 RPMs.

The next question is what RPM speed does a motorcycle operate at when it is idling? It depends on the type of engine you have. If yours is a single-cylinder engine idle speed ranges between 1200 and 1500 RPM. If you have a two-cylinder engine it generally comes to 1000 RPM when idling.

So Does A Motorcycle Battery Charge While Idling?

A quick comparison of these figures gives us an answer to this question. An ordinary alternator requires at least 2000 RPMs to start producing current to charge the battery and motorcycle’s idle speeds stand at between 1000 and 1500 RPMs.

From this we can conclude that a motorcycle battery does not charge while idling.In the case of a single-cylinder engine there is a deficit of about 500 RPMs to get it to activate the alternator to start charging. With two-cylinder engines the deficit is about 1000 RPMs.

When the motorcycle is idling, the alternator simply does not produce sufficient voltage to charge the battery. Keeping the engine running for longer does not really make much of a difference. It still doesn’t charge the battery reliably.

Assumptions Made

We have come to with this conclusion on the basis of two main assumptions. If these change the conclusion may be different.

Firstly, we assume that you have a standard alternator which kicks in at 2000 RPMs. If you have a different kind of alternator, it could have a different threshold such that it kicks in at a lower idle speed.

Secondly, we assume that your motorcycle’s idle speed is within the average range. Some bikes have higher idle speeds. Differences could be because you have a different kind of bike or you could have had your idle speed manually adjusted. It can be done.

If you have an alternator with a lower threshold and your idle speed is higher than average, you could end up being able to charge your battery when idling.

What If The Battery Dies?

If you were under the impression that idling alone will help keep your battery charged up, then you may end up with a dead battery. What then? What is the best way to charge it?

The best way to go about it is to put the battery on a charger. It takes anywhere between 4 and 24 hours to charge a motorcycle battery to full charge when using a regular trickle charger. It depends on a variety of factors including type of charger, type of battery and if the battery was completely flat.

Check the level of liquid in the battery. If levels are low, add some distilled water up to the ‘fill line’ before charging. Check the voltage every so often to make sure the battery does not overcharge. Once it is fully charged, reinstall it and take a good long ride.

Conclusion

Does a motorcycle battery charge while idling? No. There is a minimum number of Rotations per minute below which the alternator doesn’t charge the battery. This is why your motorcycle battery probably won’t charge even if you leave it idling for a long time.

The best way to make sure your battery charges as it should is to take a good long ride out on the road. This way you achieve the required RPMS to get the alternator to kick in and maintain this speed long enough for the battery to have its fill.

Post Views: 28
Post Tags: #Batteries#Deep Cycle Batteries

Related Posts

  • How to recondition batteries: Complete Guide to car battery care
  • AGM vs. Gel – which between the two battery types is better for your car?
  • Optima RedTop vs YellowTop Battery: What is the Difference
  • Battery Terminal Corrosion Causes, how To Remove, Prevention
  • Optima Battery Vs AGM Battery Review

Optima RED TOP Batteries

Very Highly Rated Batteries


Optima Batteries 8004-003 

Optima Batteries 8004-003 34/78 RedTop Starting Battery
Take a Peak

Prices pulled from the Amazon Product Advertising API on:

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.


Optima Batteries 8020-164

Optima Batteries 8020-164 35 RedTop Starting Battery
Take a Peak

Prices pulled from the Amazon Product Advertising API on:

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.


Optima Batteries OPT8022-091

Optima Batteries OPT8022-091 8022-091 75/25 RedTop Starting Battery
Take a Peak

Prices pulled from the Amazon Product Advertising API on:

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.


Optima Yellow Top Batteries


Optima Battery 8171

Optima 8171-767 DS46B24R Yellow Top Prius Battery
Take a Peak

Prices pulled from the Amazon Product Advertising API on:

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.


Optima Batteries OPT8014-045 

Optima Batteries OPT8014-045 8014-045 D34/78 YellowTop Dual Purpose Battery
Take a Peak

Prices pulled from the Amazon Product Advertising API on:

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.


Optima Batteries OPT8040-218

Optima Batteries OPT8040-218 D35 YellowTop Dual Purpose Battery
Take a Peak

Prices pulled from the Amazon Product Advertising API on:

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.

Affiliate Disclosure

We are an affiliate. We hope you like our recommendations! Just so you know, we may collect a share of sales or other compensation from the links on this website. Thank you for using our links, it helps to grow our website.

  • Privacy Policy
  • Affiliate Disclosure
  • Contact Us
  • About Us
  • Cookie Policy
  • Privacy Statement

© 2023 MotorBeast Motorbeast.Org

Manage your privacy

To provide the best experiences, we and our partners use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us and our partners to process personal data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.

Click below to consent to the above or make granular choices. Your choices will be applied to this site only. You can change your settings at any time, including withdrawing your consent, by using the toggles on the Cookie Policy, or by clicking on the manage consent button at the bottom of the screen.

Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Statistics

Marketing

Features
Always active

Always active
Manage options Manage services Manage vendors Read more about these purposes
Manage options
{title} {title} {title}
Manage your privacy
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage vendors Read more about these purposes
Manage options
{title} {title} {title}
Scroll to top
  • Autos
  • Audio
  • Bikes
  • Batteries
  • Detailing
  • Oils
  • Parts
  • Questions
  • Roof Boxes
  • Scanners
Search