Kobalt 40V Battery Not Charging: How to Fix?

Kobalt 40V Battery Not Charging: How to Fix?

Kobalt is a popular brand known for its high-quality power tools and outdoor equipment. Their 40V battery-powered tools are a favorite among DIY enthusiasts and professionals alike due to their power, reliability, and ease of use.

However, like any other battery-powered tool, the Kobalt 40V battery may encounter charging issues over time. This can be frustrating, especially if you have a project to complete. But fret not, in this guide, we will discuss the possible reasons why your Kobalt 40V battery is not charging and how to fix it.

What Is Kobalt 40V Battery?

The Kobalt 40V battery is an advanced lithium-ion (Li-ion) battery meticulously engineered to provide reliable and long-lasting power to a wide range of Kobalt tools. From string trimmers and leaf blowers to chainsaws and lawnmowers, these batteries are highly sought-after for their exceptional performance.

What Is Kobalt 40V Battery?

With a remarkable high energy density, the Kobalt 40V battery delivers optimal power output while maintaining a lightweight and ergonomic design. Its cutting-edge technology ensures that it can hold a charge for extended periods, allowing you to tackle your projects with uninterrupted efficiency.

Whether you’re a professional landscaper or a DIY enthusiast, the Kobalt 40V battery is the perfect companion for all your outdoor power tool needs. Experience the convenience and reliability that this remarkable battery offers and take your projects to new heights. [2]

Reasons Why The Kobalt 40V Battery Won’t Charge

If you’re experiencing charging issues with your Kobalt 40V battery, there could be several possible reasons behind it. Here are some common causes that can prevent your battery from charging:

  • Faulty Charger: The most common reason for a Kobalt 40V battery not charging is a faulty charger. If the charger is damaged or malfunctioning, it won’t be able to provide the necessary charge to your battery. In such cases, you may need to replace the charger.
  • Loose Connections: Loose connections between the charger and the battery can also prevent it from charging correctly. Make sure that all connections are secure and free of debris.
  • Battery Temperature: Extreme temperatures can affect a battery’s performance and cause it to stop charging. If the battery is too hot or too cold, allow it to reach room temperature before attempting to charge it.
  • Battery Age: Like all rechargeable batteries, the Kobalt 40V battery has a limited lifespan. Over time, its ability to hold a charge may diminish, and it will need to be replaced.
  • Deep Discharge: If a battery is allowed to drain completely, it may not be able to hold a charge again. This is known as deep discharge and can occur if the battery is left uncharged for an extended period. [2]

Kobalt 40V Battery Terminals

First Terminal: Positive Terminal

The positive terminal of a Kobalt 40V battery is clearly marked with a plus sign (+) and is typically color-coded red for effortless identification. This design feature ensures that users can easily distinguish and connect the positive (+) end of the power tool or charger to the battery, facilitating a seamless and efficient power transfer. [2]

Kobalt 40V Battery Terminals

Second Terminal: Negative Terminal

The negative terminal of a Kobalt 40V battery is clearly identifiable with a minus sign (-) and is commonly color-coded black for easy recognition. This terminal serves the purpose of connecting to the negative (-) end of the power tool or charger, ensuring a secure and efficient power transfer. By establishing this connection, the battery completes the circuit and enables the power tool or charger to function optimally. [2]

Three Hidden Terminals

In addition to the positive and negative terminals, there are also three hidden terminals on a Kobalt 40V battery. These terminals play a crucial role in facilitating communication between the battery, power tool, or charger. They establish a seamless connection that ensures efficient charging and optimal performance. It is worth noting that any damage to these hidden terminals can potentially disrupt the charging process, underscoring the importance of handling and maintaining them with utmost care and attention. [2]

Fifth Terminal: Communication Terminal

The fifth terminal, also known as the communication terminal, plays a crucial role in facilitating seamless communication between the battery and charger. Its primary function is to establish a secure and efficient connection, allowing the battery to receive a charge effectively. In the unfortunate event that this terminal gets damaged or malfunctions, it can disrupt the charging process, leading to the battery’s inability to receive the necessary charge for optimal performance. Therefore, it is vital to ensure the proper functioning and integrity of the fifth terminal to maintain the optimal charging capability of the battery. [2]

How To Charge A Kobalt 40V Battery?

Now that we have discussed the possible reasons why your Kobalt 40V battery may not be charging, let’s delve into how to charge it correctly:

  • Use Compatible Charger: Make sure to use a compatible charger specifically designed for Kobalt 40V batteries.
  • Align The Terminals: Ensure that the terminals on the battery and charger are correctly aligned before connecting them.
  • Connect The Charger: Plug the charger into a power source and then connect it to the battery.
  • Monitor Temperature: Keep an eye on the battery’s temperature while charging and avoid charging it in extreme temperatures.
  • Unplug After Full Charge: Once the battery is fully charged, unplug it from the charger and store it in a cool, dry place.

By following these simple steps and taking proper care of your Kobalt 40V battery, you can ensure optimal performance and longevity. Additionally, regularly checking the terminals for any damage or debris buildup can also help maintain the battery’s charging efficiency. [3]

How To Charge A Kobalt 40V Battery?

Check The Charger With A Multimeter First

If your Kobalt 40V battery still won’t charge after following the steps mentioned above, it may be worth checking the charger’s functionality with a multimeter. A multimeter, a versatile and indispensable tool used to measure voltage, current, and resistance, can provide valuable insights into any potential issues with your charger. By using a compatible multimeter and strictly adhering to all safety precautions while testing the charger, you can gain a deeper understanding of its performance. If the multimeter indicates that the charger is not functioning correctly, it may be an opportune time to consider replacing it with a new and reliable one to ensure continuous and efficient charging for your Kobalt 40V battery. [3]

Clean Off The Terminals

Another simple yet effective solution to fix a Kobalt 40V battery that won’t charge is to clean off any debris or buildup on the terminals. Over time, dirt, dust, and other particles can accumulate on the terminals, creating a barrier that hinders proper electrical contact and disrupts the charging process. To address this, take a clean cloth or brush and gently wipe away any visible dirt or debris from the terminals. Pay close attention to the small crevices and corners where buildup may be most likely. By ensuring a clean and unobstructed connection, you can potentially resolve the charging issue and guarantee efficient charging performance for your Kobalt 40V battery. This simple maintenance step not only helps to optimize the battery’s functionality but also helps extend its overall lifespan, allowing you to enjoy reliable power for your tools and equipment. [3]

Check That There Is Power Getting To The Charger

If your Kobalt 40V battery is still not charging, it may be worth checking if the charger is receiving power. This can be easily done by plugging the charger into a different outlet or trying a different power source altogether. If the charger does not receive any power, there may be an issue with the power outlet or cord, and replacing them may solve the charging problem.

On the other hand, if the charger does receive power, it may indicate a malfunction with either the battery or charger itself. In such cases, seeking professional assistance from an authorized Kobalt service center may be necessary to determine and resolve the underlying issue. Trained technicians at the service center can diagnose the problem with precision and recommend the most appropriate solution. They have access to specialized tools and knowledge to identify any potential issues with the battery or charger, ensuring that the problem is addressed effectively.

Remember, it is important to address charging issues promptly to ensure optimal performance and longevity of your Kobalt 40V battery. By taking the necessary steps and seeking professional help when needed, you can enjoy uninterrupted power supply for your Kobalt tools and equipment. [3]

Check That There Is Power Getting To The Charger

Hold The Power Button

In certain situations, if you are experiencing a charging issue with your Kobalt 40V battery, you can try holding down the power button for a few seconds. This simple action has the potential to reset the battery and enable it to effectively receive a charge. However, if this troubleshooting step does not resolve the problem, it is recommended to follow the aforementioned steps or consider seeking professional assistance to ensure the issue is properly addressed. Taking these additional measures will help ensure the optimal performance of your battery and enhance your overall user experience. [3]

Troubleshoot Your Cable, Charger, Outlet & Case

If you have tried all the solutions mentioned above and your Kobalt 40V battery still won’t charge, it may be worth troubleshooting other potential factors that could be causing the issue. These include checking the charging cable for any damage or frayed wires, making sure the charger is compatible with your specific battery model, ensuring that the power outlet is functioning correctly, and even inspecting the battery case for any visible damage or defects.

Another factor to consider is the temperature. Extreme hot or cold temperatures can affect the charging capability of the battery. If you have been charging the battery in extreme weather conditions, it is recommended to bring the battery to a moderate temperature before attempting to charge it again.

Additionally, it is important to check for any software updates for your Kobalt 40V battery or charger. Manufacturers often release firmware updates that can improve the charging performance and compatibility with different devices.

By systematically troubleshooting these factors and addressing any issues found, you can potentially fix the charging problem with your Kobalt 40V battery and enjoy uninterrupted power supply for all your tools. [3]

Troubleshoot Your Battery Charge Indicators

The battery charge indicators on your Kobalt 40V battery can provide useful information regarding the charging status and any potential issues. If the indicators are not functioning correctly, it may affect the overall charging process and cause problems. In such cases, it is recommended to clean the battery terminals and ensure a strong connection with the charger. If the issue persists, it may be necessary to seek professional assistance.

Additionally, make sure to read the user manual provided by the manufacturer for specific information and instructions on troubleshooting battery charge indicators. It is also recommended to regularly check and maintain the indicators to ensure accurate readings and efficient charging. [3]

Troubleshoot Your Battery Charge Indicators

Troubleshoot Your Screen & Battery Settings

If your Kobalt 40V battery is equipped with a screen display, it may provide helpful information regarding the charging process and any potential issues. If you encounter any error messages or unusual readings on the screen, it is recommended to troubleshoot the settings and make sure they are properly configured.

You can start by checking the battery settings and making sure they are set to the recommended or default values. If you have recently changed any settings, try resetting them and see if it resolves the charging issue.

Additionally, make sure that the screen is clean and free of any dirt or debris that may hinder its functionality. By regularly checking and maintaining the screen display and battery settings, you can potentially avoid charging problems with your Kobalt 40V battery and ensure optimal performance. [3]

Consider Replacing The Battery

If none of the troubleshooting steps mentioned above work, it may be necessary to consider replacing your Kobalt 40V battery. Over time, batteries can lose their charging capability and need to be replaced. It is recommended to follow the manufacturer’s guidelines for proper disposal and recycling of old batteries.

When purchasing a new battery, make sure to choose a genuine Kobalt 40V battery from an authorized retailer to ensure compatibility and optimal performance. By regularly maintaining your Kobalt 40V battery and following the guidelines provided by the manufacturer, you can extend its lifespan and avoid potential charging issues in the future. [1]

Advantages Of Kobalt 40V Battery

Despite the occasional charging issues that may arise, Kobalt 40V batteries offer numerous advantages for users. With a higher voltage and longer run time compared to traditional batteries, they provide more power and efficiency for your tools. This means you can tackle even the toughest tasks with ease and confidence, without worrying about running out of power.

Not only are Kobalt 40V batteries powerful, but they are also lightweight and compact. This makes them incredibly convenient and easy to handle, allowing you to work comfortably for extended periods of time. Additionally, their compact size makes them a breeze to transport, whether you’re moving between job sites or simply storing them in your toolbox.

Furthermore, Kobalt 40V batteries are designed to be compatible with a wide range of Kobalt tools. This seamless compatibility ensures that you can easily switch between different tools without any compatibility issues. It also means that you can build a collection of Kobalt tools and use them interchangeably with the same set of batteries, offering a cost-effective power solution.

One of the standout features of Kobalt 40V batteries is their fast charging time. With their advanced charging technology, you can quickly recharge your batteries and get back to your projects without any unnecessary delays. This saves you valuable time and allows you to stay productive, even during demanding work sessions.

In summary, Kobalt 40V batteries not only provide more power and efficiency, but they also offer convenience, compatibility, and fast charging capabilities. With these batteries in your arsenal, you can take on any task with confidence, knowing that you have a reliable and high-performing power solution at your fingertips. [1]

Advantages Of Kobalt 40V Battery

Disadvantages Of Kobalt 40V Battery

While there are many advantages to using Kobalt 40V batteries, it is important to also consider their limitations and potential disadvantages. One of the main drawbacks is the initial cost of purchasing these batteries and their corresponding chargers. Compared to traditional batteries, Kobalt 40V batteries can be more expensive, which may not be suitable for everyone’s budget.

Another potential disadvantage is the limited run time of these batteries. While they offer longer run time compared to traditional batteries, they may still not be enough for extended or heavy-duty use. This means that you may need to have multiple batteries on hand or take breaks to recharge them during longer work sessions.

Additionally, Kobalt 40V batteries may not be suitable for all types of tools and equipment. Some high-powered tools with specific voltage requirements may not be compatible with these batteries. It is important to check the compatibility of your tools before investing in Kobalt 40V batteries.

Furthermore, like all rechargeable batteries, Kobalt 40V batteries have a limited lifespan and will eventually need to be replaced. This means additional costs for purchasing new batteries in the future. [1]

Safety Precaution When Using Kobalt 40V Battery

As with any power tool or equipment, it is important to follow safety precautions when using Kobalt 40V batteries. Some key safety tips include:

  • Always read and follow the manufacturer’s instructions for charging and using the battery.
  • Avoid exposing the battery to extreme temperatures, as it can affect its performance and lifespan.
  • Do not attempt to disassemble or modify the battery.
  • Use only genuine Kobalt chargers and batteries to ensure safety and optimal performance.
  • Keep the battery and charger away from water and moisture.
  • If you notice any abnormalities or malfunctions with the battery, stop using it immediately and seek assistance from a professional. [1]


How do you jumpstart a Kobalt 40V battery?

Jumpstarting a Kobalt 40V battery is not recommended. The battery is not designed for this type of use and attempting to jumpstart it may cause damage to the battery.

How do you reset a lithium battery?

There is no specific reset process for lithium batteries. If you are experiencing issues with your Kobalt 40V battery, it is recommended to refer to the manufacturer’s troubleshooting guide or seek assistance from a professional.

Where is the reset button on a battery?

Not all batteries have a reset button. If your Kobalt 40V battery has one, it will be located on the side or top of the battery, near the terminals.

How do you hard reset a battery?

Hard resetting a battery is not recommended and may damage the battery. If you are experiencing issues with your Kobalt 40V battery, it is best to refer to the manufacturer’s troubleshooting guide or seek assistance from a professional.

How do I force a power reset?

To force a power reset on your Kobalt 40V battery, you can try disconnecting it from the charger and removing any connected tools for a few minutes. Then, reconnect the battery to the charger and try charging it again.

Can you restart a completely dead battery?

It is not recommended to try and restart a completely dead battery. It may be damaged beyond repair, and attempting to charge it could potentially cause safety hazards. It is best to dispose of the battery safely and replace it with a new one.

Is there a hard reset button?

No, there is no hard reset button on Kobalt 40V batteries. If you are experiencing issues with your battery, it is recommended to refer to the manufacturer’s troubleshooting guide or seek assistance from a professional.

Useful Video: From trash to treasure: Revive a Kobalt 40V 2.5Ah power tool battery


In conclusion, Kobalt 40V batteries offer a powerful and efficient power solution for various tools and equipment. Their compact size, compatibility with Kobalt tools, fast charging capabilities, and long run time make them a popular choice among professionals and DIY enthusiasts.

However, it is important to consider the initial cost, limited run time, and potential compatibility issues when using these batteries. It is also crucial to follow safety precautions and avoid attempting to jumpstart or hard reset the battery.

By understanding the advantages, disadvantages, and proper usage of Kobalt 40V batteries, you can make an informed decision on whether they are the right choice for your power needs. With proper care and maintenance, these batteries can provide reliable performance for years to come. So, it is worth investing in this powerful and versatile battery option. Keep working efficiently with Kobalt 40V batteries by your side! So, always choose the most suitable power solution for your needs and ensure a successful completion of any task. Happy DIYing!


  1. https://www.manualslib.com/manual/1677454/Kobalt-Krc-40-06.html?page=5
  2. https://thedroidguy.com/how-to-fix-ryobi-40v-battery-not-charging-1145785
  3. https://portablepowerguides.com/kobalt-charger-blinking-red-green-no-light-meaning/