How to Rebuild Cordless Drill Battery Packs

An image showing Energizer Alkaline Power D Batteries (12 Pack), Long-Lasting Alkaline Size D Batteries, an example of the best cordless drill batteries

Ready to maximize your cordless drill’s potential without breaking the bank? Rebuilding your drill battery packs is the game-changer you’ve been searching for. Say goodbye to pricey replacements and hello to a sustainable, cost-effective solution.

It is no secret that you will need to replace your cordless drill battery pack at some point. But how do you approach this when it is your first time doing it? Do not fret.

In this article, we’ll walk you through the straightforward process of revitalizing your cordless drill batteries. You’ll discover the benefits, learn the ins and outs of rebuilding, and gain insights into safety precautions and understand How to Rebuild Cordless Drill Battery Packs. 

Whether you’re a DIY enthusiast or looking to save some green, we have offered you the power to rejuvenate your tools and reduce electronic waste.

Let’s dive in!

Also Read:

Can Cordless Drill Batteries Be Rebuilt?

Yes, cordless drill batteries can be rebuilt. However, the feasibility of rebuilding your cordless batteries will depend on several other factors, including the type and condition of the batteries, available tools and expertise, and the safety precautions in place.

Before we delve into the rebuilding process, let’s explore how these factors affect your ability to rebuild your cordless drill battery.

  1. Battery type and condition

Cordless drills use different types of batteries, including nickel-cadmium (NiCd), nickel-metal hydride (NiMH), or lithium-ion (Li-ion). The complexity of rebuilding these batteries will vary with their types. For instance, Li-ion batteries are the most common type today, and they are the most challenging to rebuild due to their complex internal circuitry and safety features. Thus, when reconstructing Li-ion, ensure you have the tools and expertise to rebuild cordless batteries.

Note: When rebuilding the battery pack, you have three primary options or battery types to consider.

  • Nickel Cadmium (NiCd). Consider NiCd batteries if you want a cheaper, more affordable cordless drill battery type. These units are known for their durability and affordability. However, they are heavier and have a lower capacity than newer options; hence, they will not have a longer run time.
  • Nickel-Metal Hydride (NiMH). NiMH batteries are the best if you want a high-capacity and environmentally cordless drill battery option. The units are the most popular choice for rebuilds.
  • Lithium-Ion (Li-Ion). Perhaps the most powerful battery option among the cordless drill battery sets. These units are lightweight and have a high energy density, offering a longer runtime, just what you need for your cordless power tools. However, even though the units are a premium choice, they may need additional circuitry for compatibility.

Before choosing any battery type for a rebuild, you must assess your needs and budget.

Furthermore, the current condition of your battery is another essential element you must consider before you start the rebuilding process. For instance, you can refurbish or fix the battery with minor issues, like a broken connector or discharge. However, rebuilding is not advisable if the battery is dead, damaged, or worn out, as it could cost you more, and the process might be complicated. In such conditions, it is wise to consider purchasing new battery sets.

  1. Expertise and Tools

Like construction or electrical work, rebuilding cordless drill batteries requires you to assemble specific tools and have particular technical know-how. You’ll need to disassemble the battery pack, replace the individual cells, and reassemble it correctly. If you’re not experienced with electronics or soldering, this could be a challenge, and you may need to contact experts or professionals in the field. Luckily, we will provide you with a guide on how to go about the process.

  1. Safety

Rechargeable batteries are characterized by various safety concerns, such as fires. As a result, you must be keen on adequately handling the batteries to prevent the risks of fire and other hazards. You must adhere to the safety guidelines and consider all potential risks.

  1. Cost

One of the primary motivations for rebuilding cordless drill battery packs is cost savings. When you rebuild, you typically spend less than you would on a brand-new battery pack. The exact cost difference depends on the type or conditions of batteries you choose and the tools required for the job.

Thus, before you start or decide on rebuilding your cordless drill battery, consider whether it would be cost-effective. Sometimes, when the battery is damaged or worn out, the rebuilding process can be costlier than buying a brand-new battery. So, consider the costs and compare them with what you would have used if you purchased a new battery set.

On average, rebuilding can be up to 50% cheaper than purchasing a new battery pack. This cost-effectiveness makes it attractive, especially for those looking to maximize their drill’s lifespan without breaking the bank.

Let’s now dive into rebuilding the cordless drill battery packs.

How to Rebuild Cordless Drill Battery Packs

Rebuilding your cordless drill battery pack is a practical and cost-effective way to breathe new life into your power tools. We’ll walk you through the three essential steps of the rebuilding process: disassembling the battery pack, removing old batteries, replacing the old batteries with new ones, and reassembling the pack.

Tools Needed

  • Screwdrivers and pliers for disassembly
  • Replacement battery cells (should match the voltage and chemistry of old batteries)
  • Soldering iron and solder for connecting cells
  • Heat shrink tubing for insulation
  • Electrical tape for securing connections
  • Multimeter for testing voltage and continuity
  • Safety gear, including gloves and safety glasses

Let’s get started.

Step 1: Disassemble the Battery Pack

Before you begin disassembling the battery pack, ensure you have observed safety. That is, wear protective gloves and safety glasses. Handling battery cells can be hazardous. Once you have considered your safety, locate and remove the screws or clips holding the battery packs. Ensure you are using an appropriate screwdriver to remove these fasteners. Note where you place the screws since you will need them for reassembly.

Carefully separate the two halves of the battery casing while paying attention to any hooks or clips you want to release. Ensure you are gentle enough not to damage the pack’s internal components.

Step 2: Remove the Old Batteries from the Pack

After you have opened the pack’s casing, you will see the old battery cells arranged in series. Pay attention to the battery arrangements and connections, and using a soldering iron, desolder the wires connected to the old batteries. While at it, also take note of the polarity and position of every wire for reassembly. Gently pry the batteries from their compartments and dispose of them properly at the recycling center. We have discussed some of the most effective ways to dispose of the batteries.

Step 3: Replace the Old Batteries with New Ones

First, ensure your new battery set matches the voltage and chemistry of the original ones. If unsure, you can confirm with the manufacturers about the battery specifications or use the drill’s manual. Solder the wires onto the new cells, paying attention to the polarity and secure connections. Use heat shrink tubing to insulate and protect your soldered joints.

Step 4: Reassemble the Battery Pack

Once you have soldered the batteries, place them into their compartments, ensuring you have observed the correct polarity. Reconnect the wires while following the notes or observations you made during disassembly. After placing your new batteries in the compartment, secure the case by carefully aligning the two halves of the battery pack casing and reattaching the screws and clips. Double-check that everything is securely fastened.

Step 5: Test Voltage and Continuity

Use a multimeter to test the voltage and continuity before you put the battery pack back into your cordless drill. Ensure that the voltage matches your drill’s requirements and there are no loose connections. This should do the trick, and your new batteries will be ready for use in your cordless drill.

The below video illustrates how to rebuild or replace cordless drill batteries

Battery Pack Safety

Working with battery cells, especially during the rebuilding process of cordless drill battery packs, requires utmost caution and adherence to safety guidelines.

As such, we have explored some safety precautions you must consider in the battery-rebuilding process. But first, let’s discuss some general significance of safety precautions when handling battery cells.

  • Chemical Risks

Battery cells contain chemicals that can be harmful if exposed to skin or eyes. Additionally, damaged cells can leak corrosive substances.

  • Fire hazard

Lithium-ion batteries, in particular, can be susceptible to thermal runaway if improperly handled or damaged, leading to fires or explosions.

  • Electrical hazard

Mishandling live battery cells can result in electrical shocks or short circuits, which may lead to injuries.

Recommended Safety Measures when Rebuilding Cordless Drill Battery Packs

  1. Protective Gear: Always wear appropriate protective gear, including safety glasses and gloves, to shield yourself from chemical exposure and prevent cuts or burns.
  2. Work in a well-ventilated room– Work in a well-ventilated space to minimize inhalation of fumes or gases released during the process. The gases can affect your breathing or cause respiratory diseases.
  3. Inspect the batteries. Before starting, carefully inspect the old battery cells for signs of damage, leaks, or swelling. Do not proceed with damaged cells.
  4. Discharge batteries. If possible, discharge the old batteries before removing them from the pack to reduce the risk of accidental short circuits.
  5. Soldering Safety: Ensure you have a stable surface when soldering and keep the fire extinguisher within your reach to handle accidental fires when they happen.
  6. Avoid Overheating: Be cautious not to overheat the battery cells during soldering or any other steps in the rebuilding process. Overheating can lead to dangerous outcomes. Also, isolate the negative and positive ends of the battery cells to prevent accidental short circuits.
  7. Emergency Response: Plan for responding to emergencies, such as fires or chemical exposure. Know how to use a fire extinguisher and have access to a first-aid kit. In addition, always attempt to dispose of the old damaged battery cells at places designed for recycling. Do not throw used batteries in regular trash.

How to dispose of Old or Damaged Battery Packs

  1. Recycle

The most environmentally responsible way to dispose of old or damaged battery packs is through recycling. Various battery chemistries can be recycled, for instance,  NiCd, NiMH, and lithium-ion. Battery recycling prevents the release of hazardous materials into the environment.

Many local recycling programs and drop-off centers accept old battery packs. Check with your local waste management authority to find the nearest recycling location. Some communities even offer dedicated hazardous waste disposal days.

Below are some of the recommended recycling centers that accept old battery packs. Remember, the centers can vary based on your location. However, the list contains some well-known and reputable recycling centers for battery packs.

  • Call2Recycle

Call2Recycle is a leading battery recycling program in North America. They offer drop-off locations and mail-in options for various types of batteries, including battery packs. Visit their website to find a drop-off location near you.

  • Battery Recycling Center

Many cities have dedicated battery recycling centers that accept battery packs. These centers ensure proper recycling and disposal.

  • Retailer Programs

Retailers like Best Buy and Home Depot often have collection bins for battery recycling in their stores. They accept a range of battery types, including battery packs.

  • Manufacturer Programs

Some battery manufacturers, such as Energizer and Duracell, have recycling programs or partnerships with recycling facilities. Check their websites for information on how to participate.

  • Local Hazardous Waste Facilities

Your local hazardous waste facility may accept battery packs for proper disposal. Contact them to inquire about their acceptance policies and hours of operation.

  1. Battery Retailers and manufacturers

Some battery retailers and electronics stores may have collection bins for used batteries, including battery packs. They often participate in recycling initiatives. Also, some battery manufacturers and organizations offer mail-in programs for recycling batteries. They provide prepaid shipping labels and instructions for sending in old battery packs.

Battery Pack Repair Services

While DIY battery pack rebuilding is a cost-effective option, some individuals may prefer professional assistance or lack the time and tools for the task. Below are some professional repair services available for your damaged battery packs.

  • Local electronics repair shops

Many local electronics repair shops offer services for repairing battery packs, including those used in cordless tools. These shops often have experienced technicians who diagnose issues and replace faulty components.

  • Manufacturer service centers

Some cordless tool manufacturers have authorized service centers that can repair or replace damaged battery packs. Contact the manufacturer of your cordless drill to inquire about their service options.

  • Battery Repair Specialists

Some companies repair battery packs for various applications, including cordless tools. These specialists have the expertise and equipment to diagnose and repair battery pack issues.

Apart from the various centers where you can get specialized services for your damaged battery packs, other recommended companies or organizations also specialize in repairing cordless tool batteries. If you have or can reach any of the below-listed organizations, contact them for professional services.

  • Battery Depot

Battery Depot is a reputable company that provides battery pack repair services for cordless tools. They offer services for various battery chemistries and tool brands. You can check their website or contact them for more information.


While primarily known for selling replacement parts, also provides battery-rebuilding services for cordless tools. They offer a mail-in service, making it accessible for customers nationwide.

Note: Before you decide on a repair service,  contact them or visit their website to ensure they can repair your specific cordless tool battery pack and inquire about pricing, turnaround times, and warranty options.

Professional repair services can be a convenient and reliable option for individuals seeking to restore their cordless tool batteries to optimal performance. However, having all the information you need and deciding whether the service is what you want for your cordless phone is essential.

  • MTO Battery

MTO Battery specializes in repairing and rebuilding cordless tool battery packs. They offer services for popular tool brands and various battery chemistries. You can visit their website for more details on their repair services.

  • Batteries Plus Bulbs

Batteries Plus Bulbs offers battery pack rebuild services for various cordless tool brands. They have numerous retail locations across the United States, making it convenient to drop off your battery pack for repair.

What are some Risks involved in rebuilding the cordless drill battery Pack?

Rebuilding a cordless drill battery pack can be challenging, and some risks are involved. Here are some of the dangers to keep in mind:

  1. Electrical Shock: There is a risk of electrical shock when working with battery packs. To minimize this risk, it’s essential to take proper safety precautions, such as wearing gloves and safety glasses.
  2. Battery Leakage: If the battery cells are damaged during rebuilding, they can leak hazardous chemicals. It’s crucial to handle the cells carefully and dispose of them properly if they are damaged
  3. Battery Performance: If the battery cells are not adequately matched or installed, the rebuilt battery pack may not perform as well as a new one. Following the instructions carefully and using high-quality replacement cells to ensure optimal performance is essential
  4. Fire Hazard: If the battery cells are short-circuited or overheated during rebuilding, they can catch fire. It’s important to use caution when working with the cells and avoid exposing them to high temperatures.


The process of rebuilding cordless drill battery packs offers many advantages, from cost savings to environmental responsibility and personal satisfaction. With the right tools, safety precautions, and replacement batteries, you can successfully extend the lifespan of your cordless drill battery pack while tailoring it to your specific needs.

Moreover, by choosing this DIY path, you’re actively participating in reducing electronic waste and minimizing your carbon footprint, which is a step towards a more sustainable future.

However, it’s essential to recognize that not everyone may have the time, resources, or inclination to undertake this project themselves. In such cases, professional battery repair services are readily available and can handle the job with expertise.

Whichever path you choose, whether it’s DIY rebuilding or seeking professional assistance, you’re taking proactive steps toward a more sustainable and cost-effective approach to powering your cordless tools.

So, why wait? Dive into the world of cordless drill battery pack rebuilding and enjoy the benefits it has to offer. Happy drilling!

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