Why Is My Cordless Drill Sparking?

Sparking Drill

A cordless drill is a hardworking tool. If you’ve noticed that your cordless drill is sparking, you’ve come to the right place. Today we’re going to explain why this might be happening, if the sparking is dangerous, and what you should do about it. 

Cordless drills will spark normally within the drill itself as the carbon brushes pass by the commutator. These small sparks are a normal part of the cordless drill operation. 

However, if the drill is throwing sparks outside the drill, you may have a more serious problem. Also, seeing or smelling smoke is not part of normal drill engineering. 

If you’ve had a good drill for a while, then throwing it away can feel like parting with a friend. We will try to give you some tips on repairing your drill; however, sometimes it’s time to spend the money on something new. 

Alright, let’s jump into it. 

Common Reasons a Cordless Drill will Spark 

Before discussing anything more sinister, let’s try to relieve your mind with some common reasons your cordless drill could be sparking. 

First, let’s explain what we mean by sparking. For our purposes, normal sparking would mean small flashes of sparks that are difficult to see in full light and do not leave the drill’s housing. 

More dangerous sparks would include sparks visible in a lighted room, sparks that are shooting from the drill’s motor’s housing accompanied by the smell of smoke or melting plastic. 

In this section, we discuss the benign causes of sparks in your cordless drill. We will cover the dangerous causes further on. 

Here are a few benign reasons for sparks in your cordless drill: 

  1.  Brakes within the drill 
  2. Carbon brushes on the commutator 
  3. Your carbon brushes are breaking in  

We will explain what all this means in the sections below. 

Cordless Drill Sparking When it Starts and Stops 

If your drill has a brake, then it isn’t uncommon for a drill to show some sparks within the housing when you abruptly stop the drill. 

As long as the drill isn’t spraying sparks when it is started or stopped, don’t be alarmed by a few sparks when braking. 

Note: drills are similar to snowflakes in that no two are exactly alike. So, if your drill is sparking, but your friend’s drill isn’t, know that this could be just a random anomaly due to slightly differing parts within the drill. 

Carbon Brushes Passing by Commutator 

The carbon brushes are not really ‘brushes’ at all. They were once called brushes because they used to consist of copper wires that looked like brushes. 

Today’s brushes are made of carbon, and they run up against the commutator within the drill. The commutator helps switch the magnetic field so that the drill’s motor keeps on spinning in the proper direction. 

Minor sparking can be a natural part of this process. The friction against the carbon brushes is what creates these sparks. These sparks are usually not an issue; however, if things get dirty and overly worn, you can start to have bigger problems. 

Carbon Brushes Just Breaking In 

Sometimes, when you first purchase a new tool, you will see a small amount of sparking within the drill’s motor housing. However, after the tool is used for some time, this should work itself out. 

In the next section, we will go over serious reasons your cordless drill could be sparking. Some of the issues we go over will be correctable. Others will not. 

Let’s jump in. 

Reasons For Dangerous Cordless Drill Sparking 

Remember that serious sparking would include sparks flying from the drill’s motor accompanied by the smell of smoke. If any of these things occur, you should immediately cease using the tool. 

Here are several things to look out for:

  1. Smoke coming from the motor 
  2. The battery is shorting out 
  3. Your drill’s brushes are severely defective 

Let’s get into these things further. 

Why are Smoke and Sparks Coming From Cordless Drill? 

If you have smoke and sparks coming from your drill’s motor, you’ve likely got a serious issue. 

Perhaps your drill is really old. Or, maybe someone made the drill work harder than it was engineered to operate. Whatever the reason, you’ve likely got a motor failure. 

You could have a bearing seized within the drill. If this is the case, it’s going to take some rather technical skill to fix. 

Numerous other issues can go wrong with a motor. Tinkering with the motor is not always straight forward. If you’re mechanically minded and you enjoy messing around with broken tools, then maybe you could give it a try. 

Cordless Drill Battery Shorting

It is very uncommon for modern batteries to short out. Most will automatically shut down before becoming dangerous. 

However, if your battery does develop a short circuit, you could see some smoking from your drill. The best thing to do in this situation is to keep the drill away from flammable objects. 

A new battery might fix the problem. However, if the heat has caused damage to your drill, it’s probably safe to stay on the side of replacing the whole unit. 

Cordless Drill Brushes Defective 

As we stated earlier, it’s normal to get a few sparks from your brushes within the drill. However, these sparks should not be shooting out of the drill. 

If you’re getting serious sparks, it could mean your drill’s brushes are severely worn or clogged. It is possible to clean out this area of your drill and repair the sparking. 

We’ve gone over several serious reasons for smoking, and now we will give you some tips to keep your cordless drill running strong and prevent sparking altogether. 

How To Maintain Your Cordless Drill and Prevent Sparking 

Now it’s time to share a few ideas to maintain your drill and avoid sparking. Just like a car needs regular tires and oil changes, your cordless drill should be cared for regularly. 

Here are some things you can do to improve longevity: 

  1. Oil your drill 
  2. Don’t overwork your drill 
  3. Run your drill with a full battery 
  4. Use sharp drill bits 

Oil Your Cordless Drill 

If your drill begins to run a bit rough, it could use some oil. Oil does several things for your drill. 

First, the oil will help your drill run smoothly. Lowering the friction will lower the workload placed on your drill’s motor, thus increasing your drill’s life and reducing the incidence of sparking. 

Second, the oil will cut down on heat. The less heat you have, the less sparking you should have to deal with. 

Every drill will require a different oiling procedure. Check on your drill’s make and model to ensure you get the right oil in the right places. 

Avoid Overworking Your Cordless Drill 

Remember when we talked about the bearing in your cordless drill seizing up? A common reason this can happen is when people ask their drill to do things it wasn’t made to do. 

There are a few reasons overworking your drill is bad. 

First, it causes heat. Now, any use of your drill will cause some heat, but you want to avoid overheating your tool. If you know that you have a long day of work ahead of you, consider rotating through several different drills to allow each of them to cool down in between use. 

Second, don’t force a twelve-volt drill to do the work of a twenty-volt drill. Make sure you have the right drill for the job. 

Run Your Drill With a Full Battery 

Depending on the type of battery you have, the power of your drill will begin to wane as the battery dies. 

Frequently change the battery on your drill to prevent placing undue stress on your tool. 

If you have an old cordless drill with old batteries, you might be shocked at how efficient and powerful a new drill can be with the modern lithium-ion batteries. 

Why You Should Only Use Sharp Drill Bits 

A drill works best with sharp, properly sized drill bits. If you’re trying to drill into metal, but you aren’t using metal cutting drill bits, you’re going to place unnecessary stress on your drill. 

Similarly, if you try to screw in a phillips head screw without the properly sized bit, you will just strip the screw, cause damage to the bit, not get much done, and possibly harm your drill. 

Make sure your drill bits are sharp, and your screwdrivers are properly sized. Not only will you get your project done faster, but you will also reduce the risk of sparks coming from your cordless drill. 


A cordless drill may be one of the most valuable tools in your garage. A small amount of sparking seen through the vents of your tool is completely normal. Some drills may have much less noticeable sparks. 

The sparks are only concerning if they begin to shoot out from the drill or if you see flames or smell smoke. In general, as long as your drill is running smooth, a small number of sparks shouldn’t be concerning. 

Remember to maintain your drill to prevent causes of sparking. Use a fresh battery, and oil your drill according to the manufacturer’s recommendations. 

A properly maintained drill can provide you great service for many, many years. 

12 thoughts on “Why Is My Cordless Drill Sparking?”

  1. I just bought a cordless drill that is emitting small sparks as you carefully describe in this article. Almost sent the drill back but thought to check online and found your article. Thank you for sharing this helpful information. Very useful and thoughtfully written.

    • I inherited a 18v cordless drill and it is well used. However it sparks ✨️ a fair bit on startup and a lot on stopping. I carefully pulled out one of the brushes and using contact cleaner spray cleaned the armature. It helped a little. And if I accelerate slowly and decelerate slowly there are no sparks. Could the brushes need resurfaced? The brushes look very good and so does the slip rings. Moderate burning smell remains.

      • If brushes look worn, they are replaceable if available. Not a difficult process to do if you take your time step by step. Some video on this. Some older drills have brushes that are not available. About a $30 to $40 cost plus a few hours of your time. I’m looking at a Panasonic Model EY7440 to replace brushes. It has 14.4 Li-ion batteries that are still good and seem to last a long time. Was part of a package deal with an impact unit years ago. Having a difficult time finding the WEY744OL2308 brushes at a reasonable price. Been sparking somewhat too much inside and giving off an ozone smell. Anyone knows a good source for this part?

  2. Hey Viktor,
    Thank you for this article. A week ago I ordered Total tdli200215 cordless drill, and yesterday (after polishing a door of a car, with a few brakes) I noticed a little sparking inside housing but only when stop the drill. Hope this is not something I should worry about. Also, do you recommend cordless drill for polishing and can I use WD-40 for oil this drill (probably after 6/12 months? Thanks in advance.

    • I had an old DeWalt DC984 drill sparking and smoking. It shorted out a $75 lithium battery. I took out the motor and cleaned out the brushes and wiped away as much carbon as I could see. Unfortunately that didn’t fix the problem; it still sparked and smoked (at least I used the original NiCad battery and didn’t try it with another lithium battery). I decided to just go ahead and buy a new replacement motor rather than risk another battery damaged.


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