Pocket watch batteries are small and straightforward to replace yourself if you have the right tools
You can change a pocket watch battery at home in about ten minutes if the case back opens with a straightforward screw or snap. The battery itself costs between $3 and $15, and you need only a screwdriver, a case opener tool (or a coin), and a small pair of tweezers. The hardest part is usually opening the case without scratching it—not the battery swap itself.
The catch: if your pocket watch has a screw-down case back, a sealed crystal, or a movement you are not confident handling, a jeweler or watch repair shop is the safer choice. They charge $15 to $40 for the job and can spot problems you might miss, like corrosion or a worn gasket that lets moisture in. If the watch is valuable, antique, or has sentimental weight, the cost of a professional replacement is worth the peace of mind.
Key Takeaways
- Pocket watch batteries are replaced from the case back, which either screws off, snaps off, or requires a specialized opener—check which type yours is before you start.
- You need a case opener tool (or a flathead coin), a small screwdriver, tweezers, and the correct replacement battery size, which is printed on the old battery or in your watch manual.
- The battery sits in a holder and is held in place by a metal clip or spring—lift the clip gently with tweezers, remove the old battery, and slide the new one in the same way.
- If you see corrosion, moisture, or a damaged gasket inside the case, stop and take the watch to a jeweler rather than reassembling it.
- Screw-down case backs and sealed watches should be opened by a professional to avoid damaging the threads or waterproofing.
Identify your case back type before you open it
Pocket watch case backs come in three main types, and the type determines how you open it. The easiest is a snap-off back—a flat or slightly domed case back with a small notch or lip. You slide a flathead screwdriver or coin into the notch and gently pry upward. The back pops off without tools or force.
The second type is a screw-off back, which has a threaded edge all the way around. These require a case opener tool—a small metal disc with notches that grip the grooves on the case back. You turn the tool counterclockwise to unscrew the back. If you do not have a case opener, a jeweler can open it for you in seconds. Do not force a coin into the grooves; you will strip them.
The third type is a screw-down back, which is sealed and waterproof. These are common on vintage and high-end watches and should be opened only by a professional. Forcing one risks damaging the threads and breaking the waterproof seal.
Gather the tools and find the correct battery size
Before you open the case, collect what you need: a case opener tool (or a flathead coin for snap-backs), a small flathead screwdriver, a pair of tweezers, and the correct replacement battery. You can find the battery size printed on the old battery itself—it will be a number like SR626, SR927, or LR44. Write that number down.
Take the number to a pharmacy, jewelry store, or online retailer and order the exact replacement. Batteries are cheap—usually $3 to $8—but buying the wrong size means the watch will not work and you will have to open it again. If you have lost the old battery or cannot read the number, check your watch manual or contact the manufacturer.
Do not assume all pocket watch batteries are the same size. Even watches that look identical may use different batteries depending on the movement inside.
Open the case back and remove the old battery
Place the watch on a clean, flat surface with good light. If the case back is a snap-off, insert a flathead screwdriver or coin into the notch and explore steady, gentle upward pressure. The back should pop off with a soft click. If it does not move, try a different angle or a slightly larger coin—do not force it or you will scratch the case.
If the case back is a screw-off, fit the case opener tool onto the grooves and turn counterclockwise. Turn slowly and steadily; the back will unscrew after a few rotations. Once the back is off, set it aside on a clean cloth so you do not lose it or scratch it further.
Inside, you will see the battery held in place by a metal clip or spring. Use tweezers to gently lift the clip upward. The battery will come free. Remove it and set it aside. Do not touch the movement itself—the gears and springs inside—unless you are confident you know what you are doing.
Inspect the inside for corrosion or damage before installing the new battery
Before you put in the new battery, take a moment to look at the inside of the case. The battery compartment should be clean and dry. If you see white, green, or blue crusty deposits on the metal, that is corrosion—a sign that the old battery leaked or moisture got inside. If you see moisture, dust, or a damaged rubber gasket, do not reassemble the watch. Take it to a jeweler instead.
Corrosion can damage the movement and cause the watch to stop working soon after you replace the battery. A jeweler can clean the compartment and check whether the movement is still sound. It is worth the cost to avoid putting a new battery into a watch that will fail again in a few weeks.
Insert the new battery and close the case
Slide the new battery into the compartment with the positive side facing up (usually marked with a + symbol). The battery should sit flat and level. Use tweezers to gently lower the metal clip back over the battery. The clip should hold the battery snugly without being forced.
Before you close the case, set the watch on a flat surface and listen for a tick. If you hear it, the battery is making contact and the watch is running. If you hear nothing, lift the clip again and make sure the battery is seated all the way down and the clip is making firm contact with the top of the battery.
Once the watch is ticking, screw or snap the case back on. If it is a snap-back, press down firmly until you hear a click. If it is a screw-back, use the case opener tool to turn clockwise until the back is snug—do not over-tighten, or you will strip the threads. Wipe the outside of the case with a soft cloth to remove fingerprints.
Test the watch and know when to stop
Set the watch to the correct time and wear it for a few hours. It should keep time steadily and the second hand should sweep smoothly. If the watch stops, ticks irregularly, or the second hand jumps, the battery may not be making good contact. Open the case again and check that the battery is seated and the clip is pressing down firmly.
If the watch still does not work after you have reseated the battery, or if you noticed corrosion or moisture when you opened it, take the watch to a jeweler. A professional can test the movement, clean the battery compartment, and replace the battery correctly. The cost is low, and you avoid the risk of damaging a watch that has sentimental or monetary value.
Frequently Asked Questions
Can I use any battery as long as the number matches?
The number is the only thing that matters—SR626 is SR626 whether it is made by Energizer, Duracell, or a generic brand. Buy from a pharmacy or watch supplier to make sure you get a fresh battery. Avoid very cheap batteries from unknown sellers; they may be old stock or counterfeit and will not last as long.
What if the case back will not open?
If a snap-back will not pop off, try a different angle or a slightly larger coin. If a screw-back will not budge, the threads may be corroded or stuck. Stop and take it to a jeweler rather than forcing it—you risk stripping the grooves and making the problem worse. A professional has specialized tools and can open it safely.
How long does a pocket watch battery last?
Most pocket watch batteries last one to three years, depending on how often you wear the watch and the quality of the battery. If your watch stops after only a few months, the battery may be defective or the movement may be drawing more power than normal—a sign of internal wear.
Is it safe to open a vintage or antique pocket watch myself?
If the watch is valuable or has sentimental meaning, take it to a professional. Vintage movements are delicate, and opening the case can expose them to dust and damage. A jeweler who specializes in vintage watches can open it, replace the battery, and inspect the movement for wear—usually for $25 to $50.
What should I do with the old battery?
Do not throw it in the trash. Batteries contain chemicals that can harm the environment. Take the old battery to a pharmacy, electronics store, or hazardous waste collection site. Most places accept them for free.