3 Reasons A Motorcycle Battery Will Not Jump Start

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If you own a motorcycle, chances are that you will eventually encounter a time when it will not start. The most common cause of this is a dead battery which can be resolved by jump starting. What about when you try to jump start your motorcycle and it will still not start?

Why will your motorcycle not jump start? The three most common reasons are:

  • Your battery is no longer able to accept a charge because of age or condition.
  • Your starter is not engaging the engine properly, and unable to turn it over.
  • There is an “open” in the starter circuit, preventing the proper amount of current from getting to the starter.

Trying to diagnose a motorcycle that won’t start can be frustrating and time consuming. This has happened to me many times and I’ve learned how to figure out these problems. This article will save you some time and heartburn next time you go to start your motorcycle and can’t get it started.

Why A Motorcycle Battery Will Not Jump Start

Your motorcycle electronics operate as does any other type of circuit. Your battery supplies a dc voltage to various components to power them. When the motorcycle is running, your stator steps in to help out. As in any circuit, there must be a full or closed loop in order for a circuit to operate properly.

When starting your motorcycle, your battery supplies current to your starter motor. The current is then able to return to a ground and back to the battery. If your engine will not start, it is frequently one of the components in this system that is the culprit.

If you try to jump start the motorcycle and it still won’t start, you will want to look very closely at this circuit to make sure that all of the components are working as they should.

If you try to jump start your motorcycle and it still will not start, you will need to do a little diagnosing. First, I would recommend looking at the battery. Batteries wear out over time. A properly maintained battery can last you about 5 years. A poorly maintained battery could reach end of life relatively quickly. 

As batteries wear out, there are several common issues that may occur. The first is that a battery will not be able to hold a charge anymore. This will allow you to still jump start the battery when it’s dead but it will not remain charged and will continue to need to be jump-started each time that you want to start the bike.

It is also possible for the battery to become completely dysfunctional. This will prevent it from even being able to accept a charge. That means that even if you try to jump start your motorcycle from a good power source, it still will not start. There are many different battery testing devices out there that you can use to see if your battery is still good or not. If this is the case, you will need to replace your battery to solve this issue.

If your battery is fine but the engine still will not jump start, your issue is somewhere else in the starter circuit. This means that your issue is either with the load (the starter) or with the wiring somewhere along the circuit. You can check the wiring by measuring voltage along the circuit. If you have the appropriate voltage at the battery, you can continue to work your way down the circuit.

If you find a sudden drop of voltage, you now know the general area where the open circuit is. From there you can inspect the wires to make sure that they are not broken and that connections to terminals on the starter and solenoid are still good. Also, make sure that the circuit ground is properly connected to the frame as well, as this can prevent you from being able to start.

If your battery and the wiring are in good condition, the issue is likely your starter motor. It is generally best to replace the starter motor, although it can be repaired for slightly less money.

If you want to further prove that the starter motor is the cause, you can remove the starter motor entirely from the motorcycle and run a bench test to see if it is functioning as it should. Most auto parts stores can run a bench test for you for free.

Does Temperature Play A Role In Battery Life?

Extreme temperatures can cause excessive wear on many different components on your motorcycle. Is your battery one of those that is affected by temperature? The truth is that both extreme hot and cold temperatures will affect your battery life. Either of these scenarios can cause your battery to fail shorter than expected.

Heat can shorten the life of your battery. As the temperature increases, the chemical activity inside of your battery will also increase. This will ultimately increase the rate of cell corrosion inside of the battery. The hot temperatures are basically cooking your battery which causes it to wear out much faster. 

Cold can also have negative affects on your battery. You likely have heard the term “cold-cranking amps”. This is a measure of the current that a battery can provide at 0 degrees Fahrenheit for 30 seconds straight. Oftentimes when paying for a higher end battery, you are generally paying for a higher level of cold-cranking amps. This will allow it to perform better in cold environments.

As your battery wears out, it’s ability to supply the same number of amps at a given temperature will diminish. Your battery voltage is also important when trying to survive cold temperatures. A fully charged battery will not freeze until -58 degrees Fahrenheit. A battery with a low voltage will freeze at much higher temperatures. This freezing of the water inside the batteries can entirely ruin the battery.

That is why it’s so important to keep your battery charged all winter while you’re not riding it. If the battery voltage goes low and then it experiences freezing temperatures (32 Fahrenheit) it will ruin your battery.

How To Properly Jump Start A Motorcycle

So, we have talked about what might prevent your bike from jump starting but how do you actually jump start it? First off you are going to need a set of jumper cables. You can get these at almost any auto parts store, convenience store, or even grocery stores. Now that you have your jumper cables, you are ready to connect them. 

The first step will be to connect the jumper cables to your battery. Take the red or positive lead and connect it to the positive terminal on your bike’s battery. Afterwards, take the black or negative cable and connect that to the metal frame of the bike or the negative battery terminal. You will want to avoid any painted surfaces as this can scratch or damage them.

Next you will want to connect the other positive lead to the positive terminal on the vehicle that you are using to jump start the motorcycle. Lastly, connect the negative lead to the negative terminal on the other vehicle. You may want to give it several minutes to fully charge the battery. Once the time has passed, you can start the motorcycle.

If your motorcycle battery is very hard to get access to, one trick is to connect the positive jumper cable to the starter motor nut. Clamp this on where the battery wire comes to the starter motor. Then you can connect the negative cable to ground on the frame or battery like normal. This will charge the battery for you if it is difficult to get to.

How To Prevent Battery Issues In The Future

Battery maintenance is critical to ensuring that you do not have continual issues with it. Proper maintenance will require several things on your end. The first is to make sure to maintain the proper charge levels on your battery. If you are not going to ride your bike for long periods of time be sure to disconnect your battery. The parasitic load on the battery from electrical components on the motorcycle will eventually cause the battery to drain.

Every time that your battery fully discharges and has to be recharged shortens the overall life of the battery. You will want to always do your best to make sure that this does not happen. This will also help prevent your battery from ever freezing on you in extreme cold temperatures.

It is also important that you maintain the appropriate water levels in your battery. Regularly check the water levels and if necessary, add some distilled water. This is one task that is so simple but often overlooked. Doing this will help maximize the life of your battery.

Another important thing to be aware of is corrosion developing on the battery terminals. If you ever see this, be sure to clean it off as best as you can. The corrosion can eventually prevent electrical components from working. Staying on top of cleaning this will prevent you from being caught unawares by a battery that can no longer supply it’s voltage to your various motorcycle components.

This article has been reviewed in accordance with our editorial policy.

Kyle Cannon

Kyle currently works as a mechanical engineer and graduated with a minor in automotive engineering. He loves restoring motorcycles, has a vast knowledge of how they work, and has sold his restoration projects to customers from all over the United States.

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