digital battery tester

Test and Charge a Motorcycle Battery

Batteries do not last forever. You may have noticed that older batteries do not hold a charge over time as long as they used to. While this slow decline is most noticeable in electronics, it also happens with your motorcycle battery. Over time, your motorcycle’s maximum recharge capacity slowly declines. Your battery also discharges at a faster rate as it gets older. Knowing the basics of checking and charging a motorcycle battery will help you get the most out of its lifespan.

Check For Mechanical Issues

If you think you are experiencing battery issues, take a step back. Check your bike to make sure the issues are not a mechanical one. For example, a bike that is not firing up may have a battery issue, but it might have a safety mechanism that prevents it from turning on. You can check your owner’s manual for the safety mechanism that your bike has. Some bikes won’t start if the kickstand is down. Others won’t start if the key fob is not nearby. And others won’t start if the clutch lever is not engaged.

Inspect the Battery

Before you do anything with the battery, give it a visual inspection. First, look for any damage or bloating. These present a safety risk. If you find damage or bloating, do not attempt to test or charge the battery. Skip right to replacing it.

Another issue that can hinder your battery’s performance is dirt or grime. The electrical current flow gets blocked by dirt. This can make the battery artificially weaker than it actually is. Fix the problem by cleaning the battery terminals with a soft brush.

A third common issue is corrosion. Battery terminals are made of metal. Combining this with moisture, salt, and electrical charge gives you the perfect environment for corrosion. The buildup of corrosion on the terminals hinders the battery’s performance. Clean the battery with a wire brush to remove the corrosion.

How to Test a Motorcycle Battery

Before you test your battery, you need to learn about the necessary safety precautions. Batteries provide an electrical charge. Electricity can cause injury and, in some cases, death. The #1 rule is never swap the polarities by attaching a negative to a positive and a positive to a negative. And always work in a dry location and with a dry motorcycle.

Multimeter Test

Most riders today are familiar with AGM or sealed batteries. To test an AGM battery, you need a multimeter. Set the multimeter to the DC Voltage setting. Connect the leads to the battery terminals and determine the readout. A healthy and fully charged AGM battery should have a readout of around 12.7-13.6 volts. A slightly used battery with a capacity between 75% and 100% will have a readout of about 12.5 to 12.8 volts. Finally, batteries with a capacity under 75% of their original will have a measurement of less than 12 volts. At this point, it is probably best to replace your battery.

Hydrometer Test

While you see them less often these days, there are some motorcycles that still use unsealed batteries. These batteries use a mixture of sulphuric acid and water to create the electrical charge. You can use the hydrometer test for these batteries. Start by charging the battery. Then, very carefully insert the hydrometer to draw out some of the water. Wear goggles and gloves to protect yourself from accidental sulphuric acid splashing. Then, test the specific gravity of the fluid. The measurement for each cell should be between 1.255 and 1.275. If any of the cells have a reading around 1.215 and 1.235, then it could be time to replace your battery. A healthy functioning battery will have a similar reading for each cell.

Motorcycle Battery Voltage Test

You can check the current flow produced by your battery with a motorcycle battery voltage test. To do this, you will check the battery while it’s working. If your battery is in good working condition, it should maintain a reading over 9.6 volts for about 10 seconds.

How to Charge a Motorcycle Battery

To charge your battery or place it on a battery tender, your first step is to locate the battery. Motorcycle batteries can be in several places depending on the manufacturer and build. Batteries can be under the seat, under the fuel tank, behind the cylinders, or behind a side panel.

Once you locate your battery, you have a decision to make. You can charge your battery in the motorcycle or somewhere else. What you choose to do is mainly based on personal preference and convenience.

Next, you will need to decide between using a trickle or smart charger. A smart charger will determine the ideal charging strategy for your battery’s condition. This is the most efficient and effective charging for your battery. Ultimately, you will get a longer useful life out of your battery. In contrast, a trickle charger will provide a steady low amp charge. If you use a trickle charger, look for one with an auto shut-off when the battery’s fully charged. Otherwise, it will continue to charge the battery to the point of causing damage.

How Long Does a Motorcycle Battery Take to Charge?

How long a battery takes to charge fully depends on several factors. A battery that has sulfated will take longer to fully charge than one that is not sulfated. An older battery or one that is more drained will take longer to charge fully. The quality of your charger and charging method can also impact the charging time.

A healthy battery could take between four and twelve hours to charge fully. A worn-out battery could charge for days and never reach its new full charge capacity.

Can I Charge the Battery by Leaving the Bike Idling?

While your motorcycle battery technically charges while riding, this is not an effective method for battery charging. The amount of charging that happens is minor. You also won’t be able to ever fully charge the battery. You would need to run your battery at high RPMs for a good amount of time before you get any noticeable charging. Your neighbors will not appreciate the noise this will make.

Charge and Retest

Just because a battery is low or dead does not automatically mean you need to replace it. In some situations, you may just need to recharge it. To determine your battery’s situation, you need to fully charge it and then test it again.

Connect your motorcycle battery to a smart charger. Let the battery fully charge. Once charged, disconnect it and let it sit for 30 minutes. Check the voltage at this time. Then, wait another 12 hours and recheck the voltage. Seeing how quickly the battery’s charge drops will give you an indication of the battery’s health.

If your battery is healthy but consistently draining, you may have another problem. For example, you may have faulty cables or a parasitic electrical pull from an add-on accessory. You need to fix this problem or you will continue to have the same drainage problem with your new battery.

Symptoms of a Dead Motorcycle Battery

When checking and testing your battery, watch for a few signs. These are the signs that your battery has reached the end of its useful life, and it’s best to replace it. Your battery is so dead that nothing happens because there is no power at all. You have a barely-there battery that is strong enough to give your lights a lackluster illumination.

When checking the battery, the volt reading is under 12 after giving the battery a full charge. This is a sign that the battery has reached the end of its useful life. The battery has lost a significant amount of charging capacity.

Finally, if your battery is physically damaged in some way, you should immediately replace it. Damaged or bloated batteries are an explosive time bomb waiting to happen. They can spray caustic battery acid or ignite in flames suddenly.

Maintain Your Battery

You need to maintain your motorcycle battery to get the most out of it. A decent-quality battery in good condition should be able to work after sitting for a month, not on a charge. However, the older your battery gets, the shorter this sitting time will be. If you do not regularly ride or your bike sits for an entire season, consider putting your motorcycle on a battery tender. Your other option is to disconnect the battery to prevent anything from having an electrical pull on the battery.

Batteries that sit in especially cold or hot climates will discharge faster. This makes putting it on a tender even more necessary.

Be Ready For Every Ride

Checking and charging your motorcycle battery is just one of many necessary tasks for maintaining your motorcycle. Another crucial task is purchasing motorcycle insurance. Just as you check your motorcycle battery, check your motorcycle coverage. That way, you can cruise down the road knowing that you and your motorcycle are ready for adventure.

Request a quote today and find the right policy for your coverage needs.

This site and articles contained herein are provided for general informational purposes only and are not a substitute or intended as professional advice. Please be sure to refer to your owner’s manual or consult a mechanic for information specific to your motorcycle. The information contained on this site and articles contained herein are provided on an “as is” basis with no guarantees of completeness, accuracy, usefulness or timeliness and without any warranties of any kind whatsoever, express or implied. Rider Insurance Company and its affiliates (together, “Rider”) assume no responsibility for any errors or omissions in the content of this site and articles contained herein. Any action taken upon this information is strictly at your own risk and Rider will not be liable for any losses or damages in connection with your use of this site and articles. Additional terms and conditions apply and are available at
Plymouth Rock Assurance is a marketing name used by a group of separate companies that write and manage property and casualty insurance in multiple states. Motorcycle insurance in New Jersey and Pennsylvania is underwritten by Rider Insurance Company. Each company is financially responsible only for its own insurance products. Actual coverage is subject to the language of the policies as issued by each separate company.