What You Need Before You Start
Changing a watch battery yourself takes about 10 to 15 minutes and costs between $2 and $15 for the battery itself. You will need a case opener tool (a small flat-head screwdriver or a dedicated watch case opener, which costs $5 to $10), the correct replacement battery for your watch model, and a clean, flat work surface with good light.
Before you buy a battery, find your watch model number. Look on the back of the case or in the original paperwork. Then search online for "[your watch brand and model] battery type" — you will find a code like SR626SW or CR2032. Write this down and bring it to a pharmacy, hardware store, or online retailer. Do not guess at the battery type; the wrong one will not fit or will damage the watch.
If your watch is water-resistant or has a screw-down case back, take it to a jeweler or watch repair shop instead. Opening these yourself risks breaking the seal and letting water inside. The same applies if your watch is valuable or vintage — the risk of scratching the case back or damaging internal parts is not worth the $10 to $20 you save.
Key Takeaways
- You need the exact battery model number for your watch before you start, which you can find by searching your watch brand and model online.
- A case opener tool (a flat-head screwdriver or dedicated watch tool) is essential; trying to pry open the case back with a coin or knife will scratch or crack it.
- The entire process takes 10 to 15 minutes and involves opening the case, removing the old battery, inserting the new one, and closing the case back.
- Water-resistant watches and screw-down case backs should be opened by a jeweler to avoid breaking the water seal.
- The most common mistake is touching the new battery with bare fingers, which can leave oils that shorten its life.
Opening the Case Back
Place your watch face-down on a clean cloth on your work surface. Look at the case back — you will see either a smooth metal back or one with small notches or grooves around the edge. If it has notches, use the case opener tool to fit into one of them, then gently twist counterclockwise. Do not force it; if it does not turn easily, you may have the wrong tool or the wrong direction.
If the case back is smooth with no notches, use a flat-head screwdriver to find a small slot or indentation at the edge. Fit the screwdriver tip into the slot and gently twist counterclockwise. Again, gentle pressure is key — a sudden slip can scratch the case or your hand. Once the back loosens, you can usually unscrew it by hand the rest of the way.
Set the case back aside on the cloth where it will not roll away. You will now see the watch movement (the internal mechanism) and the battery, which is usually a small silver disc held in place by a metal clip or spring.
Removing the Old Battery and Installing the New One
Look at how the battery sits in the watch. Most watches have a small metal clip or spring that holds the battery down on one side. Using a plastic or wooden toothpick (not metal, which can cause a short circuit), gently lift this clip or spring away from the battery. The battery should pop up slightly or slide out easily.
Once the old battery is out, do not touch the new battery with your bare fingers. Skin oils can corrode the battery contacts and shorten its life. Instead, hold it by the edges or use a clean plastic tweezers. Slide the new battery into the same position as the old one, with the positive side (marked with a + or the shiny side) facing up. Then use the tweezers or toothpick to gently press the metal clip or spring back down over the battery until it sits flat and find.
Before you close the case, check that the battery is not moving. Gently tilt the watch side to side — the battery should stay in place. If it shifts, the clip is not tight enough. Adjust it and test again.
Closing the Case Back and Testing
Pick up the case back and align it with the opening. If it has notches, line up one notch with the slot on the case. If it is smooth, just position it flat over the opening. Press down gently and twist clockwise until you feel resistance. Do not over-tighten; you are looking for a snug fit, not maximum force. The case back should sit flush with the edge of the watch.
Once the case back is closed, flip the watch over and check that it is running. You should see the second hand moving. If the watch does not start, open the case back again and check that the battery is seated properly under the clip. Make sure the positive side is facing up. If it still does not work, the battery may be defective — try a fresh one from a different package.
Common Mistakes and How to Avoid Them
The most frequent error is touching the new battery with bare fingers before installation. Oils from your skin can build up on the battery contacts and prevent it from making good electrical contact. Always hold the battery by its edges or use tweezers.
A second common mistake is forcing the case back open or closed. If you feel strong resistance, stop and check your tool and direction. Forcing it can crack the case back, strip the threads, or damage the seal on water-resistant watches. Gentle, steady pressure works better than sudden force.
Many people also install the battery upside down. The positive side (usually marked with a + symbol or the shiny, smooth side) must face up toward the watch movement. If the watch does not run after you close it, this is the first thing to check.
When to Take Your Watch to a Professional
If your watch has a screw-down case back (you will see a large threaded ring around the edge), do not open it yourself. These require a specialized tool and knowledge of how to re-seal the water resistance. A jeweler can do this in 10 minutes for $10 to $20.
If your watch is a luxury brand, vintage, or has sentimental value, the cost of a professional battery change ($15 to $30) is worth the peace of mind. A jeweler has the right tools, experience with different watch designs, and insurance if something goes wrong.
If you open the case back and the battery does not look like a straightforward disc, or if there are multiple batteries or electronic components you do not recognize, close it back up and take it to a professional. Some watches have non-replaceable batteries or require calibration after a battery change.
Storing Your Old Battery and Tools
Once you have successfully changed the battery, store the old one safely. Dispose of it at a pharmacy, electronics store, or hazardous waste facility — do not throw it in the trash. Many retailers that sell batteries also take old ones back for free.
Keep your case opener tool in a small drawer or toolbox for the next time you need it. A dedicated watch case opener is more reliable than a screwdriver and will last for years. If you used a screwdriver, a small flat-head one is fine to keep on hand.
Frequently Asked Questions
How long does a watch battery usually last?
Most watch batteries last between two and five years, depending on the watch model and how often you wear it. Watches you wear every day may drain the battery faster than ones you wear occasionally. If your watch stops running within a few months of a battery change, the battery may be defective or the watch may have an internal problem.
What if I drop the tiny battery and cannot find it?
Search the area where you dropped it carefully — batteries are small and can roll under furniture or into cracks. Use a flashlight and check the floor, your work surface, and any folds in the cloth you were working on. If you cannot find it after a few minutes, order a replacement battery online or buy one at a pharmacy. They cost $2 to $5.
Can I change the battery if the watch is still under warranty?
Opening the case back yourself may void the warranty on some watches. Check your warranty paperwork or contact the manufacturer before you open it. If the watch is still under warranty, it is safer to have the manufacturer or an authorized jeweler change the battery.
Why does my watch stop running even after I put in a new battery?
The most common reason is that the battery is installed upside down or not seated properly under the metal clip. Open the case back and check that the positive side of the battery faces up and that the clip holds it firmly in place. If the battery is positioned correctly and the watch still does not run, the watch may have an internal electrical problem that requires professional repair.
Do I need to clean the inside of the watch when I change the battery?
No. The inside of a watch is sealed and should stay dry. Do not use water, oil, or cleaning solutions inside the case. If you see dust or debris inside, close the case back and take the watch to a jeweler for professional cleaning, which involves opening the watch in a controlled environment.