You can change most watch batteries yourself with a small screwdriver, a battery, and about ten minutes
A dead watch battery does not mean a trip to the jeweler. Most watches use standard replaceable batteries that cost between $3 and $15, and you can swap one out at your kitchen table. The process is straightforward: open the case back, remove the old battery, note its size number, drop in the new one, and close the case. The hardest part is usually opening the case back without scratching it.
Not every watch is a candidate. Watches sealed for water resistance, vintage watches with glued-on backs, and some luxury brands are better left to a professional. But if your watch has a screw-on or snap-off case back and you can see the battery inside, you are looking at a job that takes less time than a phone call.
Key Takeaways
- You need a case opener (or a flathead screwdriver), tweezers, a replacement battery in the correct size, and a clean, well-lit workspace.
- The battery size is printed on the battery itself—write it down before you remove the old one, or take a photo of it in place.
- Snap-off case backs are easier than screw-on ones; both take under five minutes once you have the right tool.
- If the case back is glued, soldered, or sealed, or if the watch is water-resistant, do not attempt this yourself.
Gather the right tools before you start
A proper watch case opener is inexpensive and makes the job much easier than using a flathead screwdriver. Case openers come in two main types: a knife-style tool with a notch that fits into the slot on the case back, or a three-pronged tool that grips the case back from the sides. Either one costs $5 to $15 at hardware stores, drugstores, or online. If you do not have one, a small flathead screwdriver works, but you risk scratching the case.
You will also need tweezers to lift the battery out and set the new one in place—your fingers are too large and too oily. A small container or piece of paper keeps the old battery and any tiny screws from rolling away. Work in bright light, ideally near a window or under a desk lamp. Lay a soft cloth or paper towel under the watch to protect it if you drop something.
Identify the battery size before you open the case
The battery size is printed directly on the battery itself. Common sizes are SR626, SR927, SR920, and CR2032. If you can see the battery through the case back, take a close-up photo of it now. If you cannot, you will need to open the case first, note the number, close it again, and then buy the replacement. This extra step is worth it—buying the wrong size means another trip to the store.
Write the battery number down on a piece of paper or send yourself a text message. When you are at the store or ordering online, you will have the exact number in front of you. Do not guess or assume your old watch used the same battery as your friend's watch—the size matters.
Open a snap-off case back
A snap-off case back has a small notch or groove around the edge. Fit the blade of your case opener or flathead screwdriver into the notch and gently twist or pry upward. The back should pop off with light pressure—if it does not budge after a few tries, you may have a screw-on back instead, or the case may be sealed.
Once the back is off, set it on your cloth in the same orientation so you remember which way it goes back on. The battery will be sitting in a small metal holder, usually held in place by a metal clip or spring. Do not touch the battery with your bare fingers—skin oils can interfere with the connection. Use tweezers to lift the old battery out.
Open a screw-on case back
A screw-on case back has a small slot or notch cut into the edge, designed for a case opener or flathead screwdriver. Insert the tool into the slot and turn counterclockwise, the same direction you would unscrew a jar lid. The back will come off after a few turns. Do not force it—if it is stuck, try tapping the handle of your screwdriver gently with a small hammer to break the seal, then try again.
Once the back is off, place it on your cloth in the same position. The battery will be visible in its metal holder. Use tweezers to remove the old battery, being careful not to touch the metal contacts inside the watch. If there is a metal clip or spring holding the battery in place, lift it gently to free the battery.
Install the new battery and close the case
Slide the new battery into the holder with the positive side (marked with a + or the shiny side) facing up, unless the old battery was positioned differently. Use tweezers to position it, then lower any metal clip or spring back into place. The battery should sit flat and flush with the holder—if it is tilted or sticking up, remove it and reposition it.
Before you close the case, press the crown (the knob on the side of the watch) and listen for a tick. If you hear it, the watch is running. If not, the battery may not be making contact. Lift the clip again, remove the battery, and check that both the battery and the metal contacts are clean and dry. Reposition the battery and try again.
Once the watch is ticking, align the case back with the opening and press or screw it back on. For snap-on backs, press firmly until you hear or feel a click. For screw-on backs, insert the tool into the slot and turn clockwise until the back is snug—do not over-tighten, or you may strip the threads.
Common mistakes and how to avoid them
The most common mistake is touching the battery with bare fingers. Skin oils leave a residue that can prevent the battery from making good contact with the metal terminals inside the watch. Always use tweezers, and if you do touch the battery, wipe it clean with a dry cloth before installing it.
Another frequent error is installing the battery upside down. The positive side should face up in most watches, but check the old battery before you remove it. If it was facing down, install the new one the same way. A battery installed backward will not power the watch, but it will not damage anything—straightforward remove it, flip it, and try again.
Do not force the case back open or closed. If it is not moving with gentle pressure, you may have the wrong tool or the case may be sealed. Forcing it can crack the case or strip the threads on a screw-on back. If you are stuck after a few gentle attempts, stop and take the watch to a jeweler.
When to take your watch to a professional
If the case back is glued on, soldered shut, or sealed with a gasket for water resistance, do not attempt to open it yourself. These watches require special tools and techniques to open without damaging the seal. A jeweler or watch repair shop can do it in minutes, and the cost is usually $10 to $25 plus the battery.
Vintage watches, luxury watches, and any watch you are unsure about should also go to a professional. The cost of a repair mistake—a cracked case, stripped threads, or a broken seal—is far higher than the cost of having someone else do the job. If you are not confident, it is the right call to let a professional handle it.
Frequently Asked Questions
What if the watch still does not tick after I install the new battery?
Remove the battery and check that both it and the metal contacts inside the watch are clean and dry. Wipe the battery with a soft, dry cloth and the contacts with a cotton swab. Reposition the battery and try again. If it still does not work, the watch may have a problem beyond the battery—take it to a jeweler.
Can I use any battery as long as the number matches?
Yes. SR626, for example, is a standard size made by many manufacturers. Buy from a pharmacy, hardware store, or online retailer. Avoid extremely cheap batteries from unknown sellers; a quality battery costs a few dollars more and lasts longer.
How long does a new watch battery last?
Most watch batteries last between two and five years, depending on the watch and how often you wear it. Some watches with extra features, like a second hand or a light, drain the battery faster. When it dies, you straightforward repeat the process.
Is it safe to open a waterproof watch myself?
No. Waterproof watches have a gasket or seal around the case back that keeps water out. Opening it yourself will break that seal, and the watch will no longer be waterproof. Take a waterproof watch to a jeweler or watch repair shop.
What should I do with the old battery?
Most watch batteries contain small amounts of mercury or other metals and should not go in the trash. Take the old battery to a pharmacy, hardware store, or recycling center that accepts batteries. Many accept them for free.