How to Test Motorcycle Battery

It is pertinent for everyone who owns a motorcycle to know how to test motorcycle batteries. This is particularly important because a bad battery means hell. 

Imagine getting stuck in a deserted place because the motorcycle couldn’t kick start-which is one major sign of a bad battery. To avoid this sudden disappointment, it is vital that you know how to test motorcycle battery.

how to test motorcycle battery
Photocredis: Pixabay.com

There are some kinds of tests that you could carry out on your battery. These tests are carried out with some tools. Constantly employing these tests and tools would ensure that nothing, battery wise, takes you by surprise.

Inasmuch as tests abound for testing motorcycle batteries, not all of them would be practicable. Not all of them would do the job perfectly either. In this article, however, we would pick the ones that have shown results and would definitely be worth your time and money.

Testing Motorcycle Battery

Listed below are some of the ways one can use to test to see if the battery is still sound. On some occasions, it is possible to know that the battery is not sound by just observing the battery well. 

So, before using any test method in this article, ensure that you have properly observed the battery and can not find any obvious fault.

Here are some of the things you could check for: 

  • discoloration of the battery
  • swelling of the battery
  • damaged terminal
  • excess battery leakage
  • broken plastic.

Damaged terminals are deadly and could lead to a short-circuiting of the electrical system. You can know if there was a short-circuiting when there is a sign that something burnt or melted. When there is a short-circuiting, the battery unloads all of its power at once.

Consequently, the battery will burst open due to excessive heat. But if nothing like that happened, but there is a swell in the battery, then you must have overcharged the battery.

It should also be worthy of note that some physical damages to the battery like holes, splits, and cracks may not prevent it from working. But they are largely unsafe.

If you are making use of a wet cell, you have to ensure that the water level is not too low. If the water level is low, then you should top up distilled water. A wet cell battery should not even be left to dry up.

If a wet cell battery is dry, it can cause damage to the battery. This is because the dryness leaves the cell plates vulnerable to the actions of oxygen. At this point, sulfation occurs. And when you try charging the battery, it would only burn.

Furthermore, if water is still present in the cell but dirty, this is yet another sign that the battery is not in good condition. The same effect five dirty cells have is the same effect one dirty cell would have. Hence the need to either replace the dirty water with a fresh supply or change the battery entirely.

Again, before you start testing the battery for faults, there are other things that you might want to check. You could confirm that the fault is not from the fob which may be using a battery.

You can also check other stuff on the bike that can cause your bike not to start. 

Do you have the side stand up? Did you pull in your clutch? Some modern bikes would not start unless you do those two things. These might not be faults from the battery, but they sure would prevent your motorcycle from starting.

How To Test Motorcycle Battery

There are five methods used to test motorcycle batteries. They are:

1. The headlamp test. The brighter your headlamp is, the stronger your battery.

2. The voltage reading test for AGM and Lead acid batteries carried out with a multimeter.

3. The voltage cranking test done also with a multimeter.

4. The current draw exam, carried out with a load tester and the last is a

5. The load test, carried out with a hydrometer.

The Head Lamp Test

One of the fastest ways to test the battery of your bike is doing the headlamp test. You do not need much to do this. Just switch on the headlamp of your bike and go before the bike to see how bright your headlamp is.

Usually, a dim or weak headlamp is a perfect sign that your battery cannot start the motorcycle. This only works if the motorcycle headlamp can come on without running the motorcycle. So, this will not work for those motorcycles that require you to start the bike first before switching on the lamp.

However, there is a way around this. But this is only if you are in a garage or a workshop. What can you do? You can connect a headlamp to your battery and see how bright or dim the light is.

The Voltage Reading Test

The voltage reading of the battery is another sure way to determine if the battery has a charge or not. Do note, however, that the voltage test is not for every battery out there. The test is only for AGM batteries and Lead-acid batteries.

Batteries that are not any of the above named, like Lithium batteries, may have another way to test them. If you have these, then consult the producer of your battery.

So, how do you test the voltage of the battery? Quite easy. You just need to get a multimeter. The multimeter is also referred to as a digital volt and ohmmeter. It is called DVOM for short.

For you to know how much charge is present in the battery, you have to connect the leads to a multimeter. The lead-in black color would have to go to the port which is labeled “COM.” This stands for common ground.

The lead-colored red would have to go to the port which is labeled “V.”  Tune the multimeter so that it is on the twenty volts DC part of its scale. Some of the multimeters like the auto-ranging meter do not have the scale, so you can tune the multimeter to the “V”.

Be sure that the motorbike is turned off completely before doing all of these. Place the lead-colored black to the battery’s negative terminal. Place the lead-colored red to the battery’s positive terminal. You can now check the voltage of your battery.

Now, the battery of motorcycles and even cars are twelve volts. But if the battery is 12 volts only, then you have a challenge. Your battery is low. Below is a table that shows the battery voltage and the equivalent charge it has:

VoltageEquivalent Charge
Below 11.9 Discharged
11.9Forty percent
12.06Fifty percent
12.2Sixty percent
12.5Eighty percent
12.62Ninety percent
12.73 and aboveOne hundred percent

If the battery is full, you can go on to ride your bike. If it is less than a hundred percent, you have to charge before you ride. If it is below forty percent, you may add getting a new battery to your options in case charging it does not work.

Video: How To Test Motorcycle Battery

This video takes you through how to test motorcycle battery.

Voltage Cranking Test 

This can be done by any mechanic workshop around you. You can also carry out the test at home all by yourself. For this test, which is also known as the load test, you also make use of the digital voltmeter that was used to do the voltage test.

Unlike the voltmeter test, the cranking test can only be used when the battery is fully charged. This is the only way to get a result that is correct.

How can you do the voltage cranking test? 

To do the voltage cranking test, do the following:

1. Pull up the seat of the bike and make sure that you can reach the terminals of your battery. You do not have to disconnect your motorcycle battery because you would need the charge to start your motorbike.

2. Connect the digital voltmeter exactly the way you connected it while taking the voltmeter test. Place negative lead to negative terminal and the positive lead to positive terminal.

3. You can get an extra hand to help in starting the bike. As the starter spins, you can check the voltage. If the battery is in good shape, then the voltage should not be lower than 9.6 v in a period of ten seconds.

When you carry out this test and find the voltage dropping, there is an error. If the voltage just drops to zero, then that is even a bigger problem. This problem is called an open cell. It is caused by the sulfation as mentioned earlier.

This test is carried out with a load because open cells tend to give false voltage results when you do the voltage reading test. But the true voltage exposes the true voltage that is contained in the battery. 

Any battery that fails the load test may not serve better if charged. The best thing is to replace the battery.

Current Draw Exam

If you have the toaster, also known as load tester, you can use it to test the battery. There is no one rule for testers for all batteries. Many manufacturers have testers with unique ways of measuring current. 

Hence, it is important that you check the user manual of the tester. The current draw exam is said to be better and more liberal than the voltage cranking test. Carbon stacks tend to act like a real electric load. 

It would hook up if the handler pressed the button that is spring-loaded. This adds electric load and helps you check out how the battery is performing or would perform under load.

Using A Hydrometer (Temperature-compensated) To Carry Out The Load Test

The hydrometer is not that expensive. You can use it to carry out the load test. The use of the hydrometer is to check for the battery’s specific gravity. This is a very viable way of checking how much charge is present in the battery.

How so? The battery’s specific gravity decreases as the battery discharges. So, you could say that specific gravity is directly proportional to the current present in the battery. This is also evident since the gravity increases as you charge your battery.

The hydrometer is used for checking the density of a liquid against that of a similar quantity of water. Batteries with lead-acid cells have gravity that equals 1.265 when the temperature is at 80 degrees F.

So, to read the gravity at varying temperatures here is what to do:

Add 0.004 per 10 degrees above 80. Then subtract 0.004 per 10 degrees under 80 degrees.

Starting A Motorcycle With A Battery That Has Lost Charge

One of the commonest ways of doing this is to push-start the motorcycle. You have to sit astride the motorbike and get one or two persons to push the motorcycle.

Push-starting The Motorbike

Slot in your key and make sure the ignition is on. When this is done you can set the bike to the second gear. This would help make sure the motorbike does not twitch.

The motorcycle would have to be moving at, at least five miles per hour for this to work. When this speed is achieved, you quickly drop the bike’s clutch. Push the motorcycle starter again.

As soon as the engine roars to life, pull your motorbike’s clutch in and rev up the engine a little bit. After that, you are good to go.

When you are alone and have no one to push the bike for you, get it to a hilly area or a small incline. Safely and slowly get the bike to roll and gain speed. Push the bike on the left side.

Once the five miles per hour speed is achieved, you can jump on the bike and drop your clutch. Push your starter; as soon as the engine roars to life, pull back your clutch in. Rev your bike and ride away.

Another method of getting your motorcycle started even when the battery is low or dead, is by jump-starting the motorcycle.

How do you jump-start a motorcycle?

To jump-start a motorcycle, do the following:

1. Get a charged battery, join the positive terminal of the dead battery, and the charged one using red cables.

2. With your black cable, join either engine or chassis to the dead battery’s negative terminal.

3. When the engine comes to life, detach the cable at the negative terminal, then remove the red one on the battery’s positive side. Ensure that the two wires do not touch themselves.

In conclusion, it is important that we pay more attention to our motorcycle batteries. Most times, we do not care about the battery until damage occurs or the battery has completely lost charge. This attitude should change. For the good of the rider and the longevity of their battery.

Here are some other posts that you might be interested in:

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What is a scrambler motorcycle?

How to prevent motorcycle theft

How to buy a used motorcycle

How dangerous is riding a motorcycle

How To Test Motorcycle battery – Frequently Asked Questions

What Should A Fully Charged Motorcycle Battery Read?

A fully charged motorcycle battery must read 12.6 volts. If the battery reads anything that is below 12, after testing, then you need to recharge the battery. When you have recharged, let the battery rest for some time and then carry out another test.

When you do, the battery will read 12.6 volts. if the battery has dropped up to 11 volts then you have to get yourself another battery. Such a battery is too cold and dead to pick up charge.

Why Do Motorcycle Batteries Die Too Fast?

Motorcycle batteries die too fast chiefly because of lack of proper maintenance. The next reason is improper charging and dehydration. They contribute to what makes batteries die off quickly. Slow discharge is also responsible.

There are applications in the motorcycle that also drain battery life, like the clocks, radios, alarms. Even when the motorbike is off, these apps keep draining the battery. Lastly, even if the battery does not have any load on it, batteries will discharge on their own.

How Do You Know If Your Motorcycle Battery Is Dying?

You know if your motorcycle battery is dying if the sound of your horn is low and the indicator lights are dim. Turn on your ignition but don’t turn the engine on. Now go to the horn button and press it. Put the indicators on too.

If these two respond and work, then your motorbike is alive. If the sound of the horn is weak and the lights from indicators are dim, then that is a sign that your battery would soon go dead totally.

Can A Completely Dead Motorcycle Be Recharged?

A completely dead motorcycle can be recharged and brought back to life. If you had a case of your battery dying, you can jumpstart the bike or you can use battery charger to charge the battery. However, you should not make this a habit.

Do not always allow the battery of your motorcycle to lose all of its charge before you take steps to recharge it. Lead-acid batteries deteriorate every time they die, and this damage is irreversible

How Long Does It Take A Motorcycle Battery to Die?

A motorcycle battery without load will discharge in two to three months. If the battery is still relatively new, it can stay up to five months before completely losing charge. If the batteries are old batteries, a vast number will last for just two months.

It should no longer be surprising that motorcycle batteries will discharge even if you are not using them. A lot of things are in the motorcycle that draws power and current. This speeds up the rate by which the batteries discharge.

Can A Battery Be Bad If It Reads 12 Volts?

A battery cannot be bad if it reads 12 volts. A battery reading 12 volts is one sure proof that the battery is in great condition. if the battery has 12 or more volts, then the issue is not with the battery but with something else.  

You can check to see if the connection between terminals and battery are good. If they are not, you can use jump leads to correct this. Place the leads on your terminals so that the proper circuit would be established to start the motorbike.