Complete Tutorial About Motorcycle Battery Voltage And Testing

Motorcycle Battery Voltage

The voltage of a motorcycle battery is an important number…

But why?… and what does it even mean?

Don’t worry.

I’ll tell you everything you need to know and how to read voltage numbers, and understand what it means for your battery.

How Many Volts Is a Motorcycle Battery? Are Motorcycles 12v or 6 V?

Most motorcycles use 12-volts batteries. But some older motorcycles and lighter dirt bikes sometimes need 6-volts batteries instead.

If your motorcycle is relatively recent… like it wasn’t built around WW2, it probably uses a 12-volts battery.

Some dirt bike models use less powerful 6-volts batteries since they have a very minimalist electrical system.

12volts would be overkill since they don’t require a lot of power.

If you want a bulletproof answer to know what voltage of the battery your motorcycle need, refer to your owner manual.

But in most cases, for any motorcycle, it will be 12-volts.

How Do I Know if My Motorcycle Battery Is Bad?

A motorcycle battery must be replaced if there is any fluid leaking or crack or bulging of the battery casing.

A reading under 12-volts with a multimeter after a full recharge indicates a battery being close to the end of its useful life.

If you can see apparent damage or deformation on your battery plastic case, don’t take any chance.

Do not reuse it, do not recharge it, and take it out of your motorcycle. A damaged battery is a safety hazard.

If you use a battery in this state, It’s a ticking time bomb that will eventually explode and spray acid all over… or ignite in flames… good stuff.

How to Test Your Motorcycle Battery to Know if It Is Bad?

To test your battery, you will need a special tool called a Multimeter or also referred to as a Voltmeters.

They look like this

Motorcycle battery voltage multimeter voltmeter

You can get the one I recommend by clicking here.

Otherwise, you can get a multimeter at your local hardware or auto part store.

We will first test your battery ”At rest”.

It means that the motorcycle needs to be turned off or, better yet, not have the battery connected to the bike.

Keep in mind that cold temperatures negatively affect batteries voltage. It would be better if you could perform any battery test at room temperature.

20 Celcius – 68 Fahrenheit.

For that test, we also need the battery with the best charge it can hold.

That means; fully recharged.

That is because batteries lose charge over time.

If you rode the bike recently for a decent amount of time, this is probably already taken care of.

For instance, if you rode for hours yesterday, your battery should be full already, and you can proceed to the voltmeter test.

If the bike hasn’t run for a while (1-week or more), we need to recharge the battery to get a proper multimeter reading.

-If the bike can start, ride around for a couple of hours. It gives time to let the alternator recharge the battery.

-otherwise, have a battery charger recharges the battery overnight.

motorcycle battery charger

You can get my preferred motorcycle battery charger by clicking here.

After the battery is a recharged as it can get, we can proceed with the test.

First Test – Testing at Rest

Put your multimeter to DC 12 Volt, or if your multimeter doesn’t have that function put it to V – DCV.

Motorcycle multimeter voltmeter battery voltage

Otherwise, refer to the instruction manual for your multimeter setting to test a 12-volt battery. 

Put the end tips of the multimeter leads on both battery terminals and maintain them there.

Red on positive – Black on negative.

Motorcycle Battery voltage testing
Make sure you have a solid contact between your battery terminals and your multimeter leads.
Motorcycle Battery voltage testing

At this point, your multimeter should give you a reading.

It would look something like this

Motorcycle Battery Voltage

So 12.71 volts… what does it mean?

That number represents the voltage of your battery ”at rest”.

Depending on the number, it will give insight into the state of your battery and what amount of charge is in there.

It is more or less what these voltage numbers represent for a 12-volts motorcycle battery.

12-volt motorcycle battery voltage chart

Keep in mind that this is a rough estimate. It will vary from a battery model and one type of battery to another.

Also, remember that not all voltmeters are created equal, and there are some margins of error of more or less 0.2 volts between models.

But if you got a result between 12.50 volts to 14.00 volts you’re good.

Over time, your battery capacity to recharge and hold a charge will diminish.

For instance, when your battery was brand new, it could probably go up or close to 13.00 volts.

But three years later, after regular usage, the same battery might only be able to take up to 12.50 volts charge. It would represent around 75% capacity, and your battery can no longer go higher than that.

Your battery will also discharge quicker as it gets older.

I saw some batteries being fully charged, only to be dead the next morning.

As your battery decay and goes bad, its best charge will be too weak to start your motorcycle.

If you got a decent voltage number, good, let move on.

We need to do the second test to test if your battery is good or bad.

What Is a Bad Battery?

As a basic rule of thumb, if the number is close or below 12 volts, such as 11.95v, for instance, you should replace the battery.

When a motorcycle battery is empty or ”dead”, it will not read absolute zero but something around 10.5 volts or lower.

If it read zero or close to zero, something is wrong and improperly connected inside your defective battery, or there is a short circuit somewhere.

Second Test – Under Load Battery Test

For this test, we will find out how your battery reacts when it is ”Working”.

By the way, you probably will need a second pair of hands for this, so find a friend :).

You also need the battery to be connected to your motorcycle this time.

1.The same thing as before, hold the end tips of your multimeter lead and have them touching their respective colors terminals.

2.Now ask your helping friend to start up the bike or try to start it.

When the ignition button is pressed, and the electric starter starts moving, this will put the battery ”under load”.

3.You will see a significant drop in the multimeter reading and rise back up when the motorcycle engine catches.

That normal.

Suppose you saw 9.5 – 10.5 volts, that good. That means your battery is in decent ”Health.”

If you saw the reading drop below 8.5volt, your battery is getting tired and does not work well under load.

In that case, You should replace it soon.

Motorcycle Battery Voltage Could Be Too High

A battery can have too much of a recharging voltage. A reading of 14.8volt and above indicate there is something wrong with the electrical system.

Turn off your bike to avoid damage if you see anything above 14.8volt

The problem is probably your Rectifier-Regulator.

It is the part of your motorcycle that takes the raw electricity generated by your alternator and regulates it to a safe voltage.

12.00 to 14.50volt is considered a standard voltage when a motorcycle is running.

Motorcycle Battery Voltage to Start

A Healthy motorcycle battery should read above 12.20 volts at rest and between 9.5v and 10.5v on the bike start-up. After the engine has caught, 12 to 14.5V is considered normal.

14.8v and above indicate a problem, and the battery is overcharging.

What Is the Minimum Voltage of A Motorcycle Battery?

If you have a 12 Volt battery reading 10.5v or below, your battery is empty and dead.

11.95volts at rest after a recharge means that your battery will need to be changed soon.

Under load, your motorcycle battery should not read below 8.5volts.

If a motorcycle battery reads 0volts or close to it, it means the battery is internally defective. The other explanation is that there is a short circuit somewhere in the electrical system of the bike.


So there you have it. I hope you found my little tutorial Useful about motorcycle batteries voltage.

If you are stuck somewhere with a bad battery and your bike won’t start, I got a full tutorial on jumping-start your motorcycle with a car.

You can click here to read the illustrated tutorial.

Hope to see you on the roads.

Take Care, Ride Safe.