Modern bikes with Internal Combustion Engines (ICE) all need a battery to crank the motorcycle on and supply current for the bike’s electrical system.
In fact, without a battery to power the electrical systems of your motorcycle, such as the headlight and indicators, it isn’t considered street legal.
Modern-day motorcycles have 12-volt batteries. Older Motorcycles were powered by 6-volt batteries, but that time is long gone.
A 12volt motorcycle battery typically ranges from 10.5 volts to ~14.5 volts, when in good shape.
Table of contents
- What are the different types of batteries?
- How to tell whether your motorcycle’s battery is 6v or 12v?
- What is the general range of voltage across a 12v battery?
- How should I test my motorcycle battery charge?
- What is the life of a motorcycle battery?
- How can you take care of your motorcycle batteries?
- What to do if your motorcycle battery is flat?
- How many volts are Harley Davidson batteries and what about other superbikes and supersports?
What are the different types of batteries?
Broadly speaking, there are 4 different types of batteries.
- The conventional Lead Acid battery with the acid floating freely within the battery is the most common. This battery poses a real spill risk of acid should you crash. The battery must be mounted in an upright position. This battery requires regularly topping up with distilled water to maintain the electrolyte level and is the cheapest of the four.
- The next is the AGM – Absorbed Glass Mat battery. This runs on the same principle as the Lead Acid batter, except that the acid is absorbed into spongy fiberglass sheets preventing spills. This is also sealed and does not require you to top up the distilled water.
- The 3rd kind of battery is the Gel battery. This is similar to the Lead Acid battery, except that adding some silica to the acid makes it a gel and, therefore, spillproof. These last longer than the standard Lead Acid battery but are also more expensive. These, too, are maintenance-free.
- The 4th kind of battery is the Lithium Ion based battery. This battery is lighter and can be mounted in any manner, whether sideways or upside down. There is no chance of a spill. And it is much lighter than the others and completely maintenance-free. These typically outlast all other batteries but are also more expensive.
How to tell whether your motorcycle’s battery is 6v or 12v?
There are several ways to determine the voltage of your battery.
- Check the label on your battery. The label on your battery should clearly tell you the voltage.
- Check the shop manual for your bike.
- Use the voltmeter or multimeter to check the voltage.
- Google it and check from a couple of sources.
What is the general range of voltage across a 12v battery?
For a 12v battery, here is a table to help understand the range of voltage variations and what each means.
| Voltage | State of charge | Will the bike start | Charge? |
| 12.7v + | 100% | Yes | Smart charge |
| ~ 12.5v | 75% | Yes | Trickle or Smart charge |
| ~ 12.3v | 50% | No | Trickle or smart charge |
| < 12V | Discharged | No | Trickle charge |
How should I test my motorcycle battery charge?
It is essential to be familiar with the performance of your battery in some common scenarios. Let’s look at them one by one.
To get started, connect the terminals of your Voltmeter or Multimeter to the battery terminals. The negative terminals of your measuring device and battery should be connected. Similarly, the positive terminals of the device and battery should connect to each other.
Turn on the measuring device to DCV. Now, setup each of the following scenarios:
Scenario 1: Open circuit voltage, kill switch OFF, and ignition OFF.
The voltage should be in the high 12Vs. This could be anything higher than 12.7V. As long as the voltage exceeds 12.7V, the battery is charged, and things look good.
Scenario 2: Kill switch ON, ignition ON, but DON’T start the vehicle (engine OFF)!
At this time, the headlight and the electronics will get powered. This should trigger a very slight voltage drop. The voltage should still be in the 12s even though it might be in the low 12s.
However, if there is a greater voltage drop, that might indicate a problem with the battery.
Scenario 3: Kill switch ON, ignition ON, and engine turned ON and running at IDLE!
Now it’s time to put a significant load on the battery to see how it performs. If the voltage drops between 9.5V to 10.5V with the bike cranked and the engine running, things are still good. It would be better, of course, for it to be in the 10s instead of the 9s. Anything above the 10V marker on cranking the bike would have been ideal.
However, if the voltage drops to less than 9.5V, there could be trouble. This could mean one of two things.
Either the battery is not on a full charge, or the battery life is nearly over. It is important to note that seeing an undercharged new battery might simply require plugging the battery into a charging system. However, undercharge on older batteries usually signals that the battery may need a replacement.
Scenario 4: Kill switch ON, ignition ON and engine turned ON, and RPM about 2500
Open up the throttle slightly to go above the 2000RPM mark. We are trying to check the charging voltage of the battery. If the battery voltage crosses the 14V mark, then the battery is in good shape. If it is lower, you might want to consider getting the charging system of the motorcycle inspected along with the battery, of course. One or both of them could be the culprit.
What is the life of a motorcycle battery?
When taken good care of, Lithium batteries can last 5-7 years.
A conventional battery such as a Lead-acid battery, and an AGM battery, on the other hand, will last 2-4 and 3-5 years, respectively, with good care.
How can you take care of your motorcycle batteries?
You want to pay attention to your batteries because you rely a lot on them.
Imagine being in a remote place, far away from the city, with no motor mechanics nearby and suddenly having a dead battery on your hands!
No one wants that. But you must be mindful and take good care of the battery to avoid such situations.
Here’s what you should keep in mind to take good care of your battery.
Take care of your motorcycle battery in cold weather.
While a Lithium battery takes the most hit, Lead Acid batteries fare slightly better in nasty cold conditions.
If you know that your motorcycle will sit in the winter and you will not be riding much, it’s best to remove the battery and store it in a warm place.
???? If you do, however, want to keep the battery in the motorcycle, consider using a Battery Tender. A Battery Tender, like its name suggests, tends to the battery. It is essentially a battery charger that maintains the charge on the battery when it is not in use.
Using your motorcycle regularly to maintain the battery
A battery performs best and lasts the longest when it is regularly used.
If you ride your motorcycle for 30mins on average every day, then this keeps the battery charged and in use. This will increase the overall life of the battery as well.
However, suppose 30 mins are all you ride in 2 weeks or so. In that case, you will need to support the battery with a smart charger or else risk degrading the life of your battery.
Topping up the distilled water on the Lead Acid Batteries of your motorcycle
Lead-acid battery maintenance requires topping up distilled water regularly. A good rule of thumb is to inspect your Lead Acid battery at least once every two months. You should inspect even sooner in the summer months or when you ride more often. The more the battery is in use the faster the electrolyte depletes.
If the level of distilled water goes down below the specified markers and is not topped up immediately, it can lead to a degradation of the lead battery plates permanently and cause a fall in the battery power. The fall in the overall output of the battery will be permanent and even if fully charged the battery will never be able to achieve the original output.
Charging your motorcycle battery correctly.
Lead-acid batteries, AGM batteries, and Gel batteries can be charged using a trickle charger. Trickle chargers simply keep pumping a small charge constantly and need monitoring. The important thing to note about using a trickle charger is that the rating needs to be similar to the voltage of the battery. So for 12-volt batteries, it is best to use a charger with a 12V rating and keep the current supply to about 1/10 of the capacity of the battery. So for a 0.9Ah battery charging it with a current of about 0.1 with a 12V charger should be good.
It is never a good idea to charge a motorcycle battery with a charger with a very high voltage capacity, such as a 24V charger! This could fry and permanently damage your battery ????!
Trickle chargers are manual chargers that can overcharge a battery if not monitored. You can use a floating charger or a smart charger instead. Floating chargers such as a Battery Tender keep charging till it achieves a full state of charge, after which it will cut off automatically. It will remain cut off till such time as the voltage remains steady. It will start charging again if it detects a drop in voltage reading.
What to do if your motorcycle battery is flat?
If you have a flat battery on your hands, try to switch ON the kill switch and turn the ignition ON. But DO NOT crank the ignition key — DO NOT try to start the bike.
If the console powers on when you turn the key to the ignition point, there is a good chance you will be able to bump or jump-start the bike.
Push the motorcycle downhill if possible and once it picks up some speed, try and engage the first gear or the 2nd gear. This should crank the motorcycle on! This might require some good physical labor. See if you can enlist the help of another person to help push the motorcycle. Both my superbikes weigh more than 450 pounds! I know what’s it like to be up against something so heavy ????! Get help!
If you happen to have jumper cables on hand, you could try to use another motorcycle battery or a car battery to jump start.
Make sure the car is turned off when you do this.
Attach the positive cable of the jumper wire to the positive terminal of the supplying battery and the positive terminal of your motorcycle battery. Attach the negative cable to the negative terminal of the supplying battery and the other end of the jumper cable to a metal part of your motorcycle, away from your battery and preferably on a non-painted part of the framework.
Here’s a great video to follow on how to jump-start your motorcycle and avoid common mistakes.
How many volts are Harley Davidson batteries and what about other superbikes and supersports?
Harley Davidson batteries are typically 12V batteries. They used to run 6Volt H3 batteries before 1965.
In 1965 Harley-Davidson came out with the FL Electra-Glide, which featured an electric starter with a 12-volt battery. Ever since Harley Davidson has been using 12V batteries.
Superbikes and sports bikes also use 12volt batteries.
Well, there you have it. I hope that this post has been helpful and informative. If you have any questions or comments, please don’t hesitate to let me know in the comment section below. And remember, always ride safe and take care of that battery!
When your motorcycle won't start on a cold morning it's not always the battery to blame, it could be a faulty choke! Learn what a choke does on a motorcycle here →.
