Yes, cordless drill batteries can often be refurbished, extending their lifespan and saving you money. Refurbishing typically involves replacing worn-out cells with new ones, restoring power and performance to your tool.
Is your trusty cordless drill starting to lose its punch? Does it die out after just a few minutes of use, even after a full charge? You’re not alone. Many DIYers and professionals find their cordless drill batteries degrade over time, leading to frustration and the urge to buy a costly replacement. But what if there was a way to breathe new life into your old battery pack? The good news is, yes, can cordless drill batteries be refurbished, and it’s often a more budget-friendly and environmentally conscious option than buying new. In this guide, we’ll explore what refurbishing entails, why it’s a viable solution, and how you can approach it, making your tools powerful again.
Understanding Your Cordless Drill Battery: The Heart of Your Tool
Before we dive into refurbishing, let’s get a basic understanding of what’s inside your cordless drill battery. Most modern cordless drill batteries are rechargeable lithium-ion (Li-ion) packs. These packs are made up of several individual cylindrical cells, often referred to as 18650 cells (though other sizes exist).
These cells are connected in series and parallel to achieve the desired voltage and capacity. Think of it like a team of workers:
Series Connection: This increases the voltage. If you have two 3.7V cells in series, you get 7.4V.
Parallel Connection: This increases the capacity (how long it lasts). If you have two 2000mAh cells in parallel, you get 4000mAh.
Inside the battery casing, you’ll also find a Battery Management System (BMS). This is a crucial electronic circuit that protects the battery from overcharging, over-discharging, short circuits, and overheating. It also helps balance the charge across the individual cells, ensuring they all work efficiently together.
Over time, these individual cells degrade. This degradation can be due to:
High temperatures: Leaving batteries in a hot car or charging them in direct sunlight is a major culprit.
Deep discharges: Consistently draining the battery all the way down can stress the cells.
High charge/discharge rates: Frequent heavy use can also contribute to wear.
Age: Like all batteries, Li-ion cells have a finite lifespan, measured in charge cycles.
When one or more cells within the pack fail or degrade significantly, the entire battery pack’s performance suffers. The BMS will often prevent the pack from being used if it detects a problem with a cell.
Can Cordless Drill Batteries Be Refurbished? The Simple Answer is YES!
Yes, cordless drill batteries can be refurbished. This process typically involves opening the battery pack, testing the individual cells, and replacing any degraded or dead cells with new ones. It’s a way to give your existing battery a second life, often at a fraction of the cost of a new pack.
Why Refurbish Instead of Replace?
There are several compelling reasons why refurbishing your cordless drill batteries makes sense:
Cost Savings: New batteries for cordless drills can be quite expensive, sometimes costing as much as a new drill itself. Refurbishing can significantly reduce this cost.
Environmental Friendliness: E-waste is a growing problem. By refurbishing, you’re diverting a battery pack from landfill and reducing the demand for new manufacturing, which has its own environmental impact.
Extended Tool Life: A refurbished battery can bring your favorite drill back to its full, powerful potential, allowing you to continue using the tool you’re accustomed to.
Learning and DIY Satisfaction: For those who enjoy tinkering, refurbishing a battery can be a rewarding project.
What Does “Refurbishing” Actually Mean for Batteries?
When we talk about refurbishing a cordless drill battery, it’s not about magically repairing the old cells. Instead, it’s about replacing the worn-out components with new ones. The most common and effective refurbishment involves replacing the individual Li-ion cells within the battery pack.
The process generally looks like this:
1. Disassembly: Carefully opening the battery pack casing.
2. Testing: Identifying which individual cells have failed or degraded significantly.
3. Replacement: Removing the old cells and soldering in new, high-quality cells.
4. Reassembly: Sealing the battery pack back up.
5. Testing: Ensuring the refurbished pack holds a charge and performs as expected.
It’s important to note that the BMS and the plastic casing are usually retained. You’re essentially giving the battery a new “heart.”
The Refurbishing Process: A Step-by-Step Guide
Refurbishing a cordless drill battery is a project that requires careful attention to detail and some basic electronics knowledge. If you’re not comfortable working with electronics or batteries, it’s best to leave this to the professionals or purchase a new battery.
Disclaimer: Working with lithium-ion batteries can be dangerous if not done correctly. They can overheat, catch fire, or explode if short-circuited or mishandled. Proceed at your own risk. Always wear safety glasses and use appropriate tools.
What You’ll Need:
Replacement Cells: The exact type and configuration of cells your battery uses. This is critical! You need cells with the same voltage, capacity, and discharge rate.
Soldering Iron and Solder: A good quality soldering iron with a fine tip.
Wire Strippers/Cutters: For preparing wires.
Pry Tools or Small Screwdrivers: To open the battery casing.
Multimeter: To test cell voltage and continuity.
Spot Welder (Optional but Recommended): For a professional and secure connection of new cells. Soldering directly to Li-ion cells can be risky if not done correctly and can overheat them. Spot welding uses thin nickel strips to join cells without excessive heat transfer.
Heat Shrink Tubing: To insulate connections and the new cells.
Safety Glasses: Essential for eye protection.
Gloves: For handling cells.
Patience and a Clean Workspace: Crucial for success.
Step-by-Step Refurbishing:
1. Identify Your Battery and Source Cells:
Carefully examine your battery pack. Note the brand, model number, voltage (e.g., 18V, 20V), and Ah (amp-hour) rating.
You’ll need to open the pack to see the exact type of cells used. They are usually marked with their model number (e.g., 18650).
Crucially, source replacement cells of the exact same specification. Reputable battery suppliers are your best bet. Do not use generic or unbranded cells, as their quality and safety can be questionable.
2. Open the Battery Pack:
Most battery packs are held together with plastic clips, screws, or a combination of both.
Use your pry tools or screwdrivers to gently separate the casing. Be patient and avoid forcing it, as you don’t want to damage the internal circuitry or the cells.
Once open, you’ll see the arrangement of cells, usually in a plastic holder, and the BMS board.
3. Document the Layout and Connections:
This is vital! Before you disconnect anything, take clear photos or draw a diagram of how the cells are connected. Note the polarity of each cell (+ and -) and how they are wired together in series and parallel.
Pay close attention to the wires connecting to the BMS board.
4. Test the Existing Cells:
Using your multimeter, carefully measure the voltage of each individual cell.
Healthy Li-ion cells should read around 3.6V to 4.2V when fully charged.
Cells that read significantly lower (below 2.5V) or show zero voltage are likely dead or severely degraded.
You can also test for internal resistance, but voltage testing is the most common indicator for DIY refurbishing.
5. Remove the Old Cells:
If the cells are spot-welded, you’ll need to carefully cut or break the nickel strips connecting them.
If they are soldered, desolder the connections. Be very quick with the soldering iron to avoid transferring too much heat to the cell, which can damage it.
Once all connections are removed, carefully slide out the old cells.
6. Install the New Cells:
Double-check the polarity of your new cells. Reversing polarity will destroy the pack.
Spot Welding: This is the preferred method. Place the new cells in the plastic holder, ensuring correct orientation. Use a spot welder to attach nickel strips to the positive and negative terminals of each cell, connecting them in the same configuration as the original pack.
Soldering: If spot welding isn’t an option, you can carefully solder wires to the new cells. Use a small amount of solder and work quickly. You might want to attach small nickel strips to the cell terminals first, then solder the wires to the strips.
Insulate: Use heat shrink tubing to insulate all connections and the sides of the cells if necessary.
7. Reconnect to the BMS:
Following your photos or diagram, carefully connect the new cells to the BMS board. Ensure all connections are secure and correctly polarized.
Make sure no exposed wires can touch each other or the casing, which would cause a short circuit.
8. Test the Refurbished Pack:
Before closing the casing, place the battery pack in your charger.
Observe if it starts charging. Most BMS systems will prevent charging if there’s a fault.
If it charges, let it charge fully. Then, test it in your drill.
9. Reassemble the Battery Pack:
Once you’ve confirmed the refurbished battery works correctly, carefully reassemble the casing.
Ensure all clips snap into place or screw it shut securely.
Can You Just Replace the Cells?
Yes, that’s precisely what refurbishing means in this context – replacing the worn-out individual cells within the battery pack. The casing and the Battery Management System (BMS) are typically reused.
Is It Worth the Effort?
For many, the answer is a resounding yes, especially if you have several older batteries that are no longer holding a charge. The cost savings can be substantial, and it’s a great way to keep your tools operational without breaking the bank. However, it does require a certain level of technical skill and comfort with electronics.
When Refurbishing Might Not Be the Best Option
While refurbishing is often a great solution, there are times when it’s better to bite the bullet and buy a new battery:
Damaged Casing: If the plastic casing of your battery pack is cracked, broken, or compromised, it might be difficult to properly seal and protect the new cells. A damaged casing can also expose the internal components, creating a safety hazard.
Damaged BMS: The Battery Management System is a complex circuit. If the BMS board itself is visibly damaged (e.g., burnt components, cracked traces), it’s usually not feasible or cost-effective to repair or replace it. The BMS is critical for safety and proper operation.
Uncertainty About Cell Type: If you can’t definitively identify the exact type and specifications of the original cells, or if you can’t find reliable replacements, it’s best not to proceed. Using incorrect cells can lead to poor performance or dangerous situations.
Lack of Technical Skill or Tools: As mentioned, this isn’t a project for everyone. If you’re not comfortable with soldering, testing electronics, or working with potentially hazardous materials, it’s safer to buy new.
Cost of Replacement Cells: Sometimes, the cost of high-quality replacement cells can approach the cost of a new battery, especially for older or less common battery types. Always price out the cells before committing to the project.
Professional Battery Refurbishing Services
If the DIY route seems a bit too daunting, or if you simply don’t have the time or tools, there are professional services that specialize in refurbishing cordless tool batteries.
These services typically:
Have the expertise and specialized equipment (like spot welders).
Source high-quality replacement cells.
Test the battery thoroughly before and after refurbishment.
Offer a warranty on their work.
Searching online for “cordless tool battery repair” or “battery refurbishment service” in your area can help you find reputable companies. While this option costs more than DIY, it’s still often cheaper than buying a brand-new battery and provides peace of mind.
How to Extend the Life of Your Cordless Drill Batteries (Even New Ones!)
Prevention is always better than cure. By following these best practices, you can significantly extend the lifespan of your cordless drill batteries, whether they are new or recently refurbished:
Avoid Extreme Temperatures: Never leave your batteries in a hot car, direct sunlight, or freezing conditions. Store them in a cool, dry place.
Don’t Store Batteries Fully Discharged: If you’re storing a battery for an extended period (more than a month), charge it to about 50-70%. Storing them fully discharged can cause irreversible damage.
Avoid Deep Discharges: Try not to run your battery completely dead. If you notice the drill’s power significantly dropping, it’s better to swap in a fresh battery and let the other one charge.
Use the Correct Charger: Always use the charger specifically designed for your battery brand and voltage.
Clean Battery Contacts: Periodically clean the metal contacts on both the battery and the charger with a pencil eraser or a soft cloth. Dirty contacts can impede charging and power delivery.
Charge in Moderate Temperatures: The ideal temperature for charging is typically between 40°F and 70°F (4°C and 21°C).
Don’t Overcharge (Generally): Modern chargers have built-in circuitry to prevent overcharging. However, it’s still good practice to remove the battery once it’s fully charged, especially if you’re not using a smart charger.
* Rotate Your Batteries: If you have multiple batteries, rotate them so they get used and charged evenly. This prevents one battery from sitting unused and degrading while others are cycled.
Frequently Asked Questions About Refurbishing Cordless Drill Batteries
Here are some common questions beginners have about refurbishing:
1. Can I just buy new cells and swap them into my old battery pack?
Yes, that’s the core idea behind refurbishing. You replace the worn-out individual cells with new ones, while keeping the original battery casing and Battery Management System (BMS).
2. Is it safe to solder directly onto lithium-ion cells?
It can be risky. Lithium-ion cells are sensitive to heat. Excessive heat from soldering can damage the cell, reduce its lifespan, or even pose a safety hazard. Spot welding is the preferred method as it applies heat for a much shorter duration. If you must solder, do so quickly and with a low-wattage iron.
3. How do I know which cells to buy?
You need to open your battery pack and identify the specific model number of the cells used (e.g., 18650, 21700). You also need to match the voltage, capacity (mAh or Ah), and maximum discharge rate (A) of the original cells. Always buy from reputable suppliers.
4. What if my battery pack has a damaged circuit board (BMS)?
If the Battery Management System (BMS) board is visibly damaged (burnt, cracked), it’s generally not recommended to refurbish the battery. The BMS is critical for safety and proper operation, and replacing it can be complex and costly. In such cases, buying a new battery is usually the best option.
5. How much does it typically cost to refurbish a battery?
The cost varies depending on the type of battery and the price of replacement cells. DIY refurbishment can cost anywhere from $20 to $60 for the cells and supplies. Professional services might charge $50 to $100 or more, but this often includes a warranty. This is significantly less than the $100-$200+ a new battery can cost.
6. Can all cordless drill batteries be refurbished?
While many can, some manufacturers use proprietary cell configurations or heavily sealed casings that make refurbishment difficult or impossible for the average user. It’s always best to check your specific battery model.
7. What are the signs my battery needs refurbishing?
Common signs include a significantly reduced run time, the battery dying very quickly even after a full charge, the battery not holding a charge at all, or the charger indicating an error with the battery.
Conclusion: Give Your Drills a Second Wind
Can cordless drill batteries be refurbished? Absolutely! It’s a practical and cost-effective solution for breathing new life into aging power tool batteries. Whether you tackle it as a DIY project or opt for a professional service, refurbishing your batteries can save you money, reduce waste, and keep your favorite tools running strong. By understanding how these batteries work and taking proper precautions, you can enjoy extended use from your existing battery packs and get the most out of your cordless tools. Remember to always prioritize safety and use quality components if you decide to embark on a DIY refurbishment journey.
