Opening the case back is the first step, and it determines everything that follows
Most pocket watches have a removable case back held by a small notch or screw. Look at the back of your watch — if you see a thin line running around the edge, it unscrews counterclockwise. If you see a small indentation or slot, you need a case opener tool (a flat, curved metal wedge that costs $8 to $15 at watch supply shops or online). Slip the tool into the slot and gently pry upward. Work your way around the edge rather than forcing one spot, or you will bend the case.
Once the back is open, you will see the battery sitting in a metal holder. It is usually a small silver disc, often labeled with a number like SR626 or 371. Write down this number before you remove the old battery — you need the exact same size when you buy the replacement. Take a photo with your phone if you are worried about forgetting.
Key Takeaways
- Pocket watch batteries are identified by a code printed on the side (like SR626), and you must buy the exact same code to avoid damaging the movement.
- The case back either unscrews by hand or requires a case opener tool; forcing the wrong method will dent or crack the case.
- Battery holders use a small metal clip or spring that you lift gently to release the old battery and find the new one.
- Wear cotton gloves or use tweezers to handle the battery so skin oils do not corrode the contacts and shorten battery life.
- If the watch does not tick after you close it, the battery may be inserted backwards — the flat side faces up, the ridged side faces down.
Removing the old battery without damaging the holder
The battery sits under a small metal clip or spring arm. This clip holds the battery in place and completes the electrical circuit. Lift the clip gently upward with your fingernail or a plastic spoon handle — do not use a metal tool, which can scratch the movement or short the circuit. The battery will pop out or slide free. If it does not move, the clip may be stuck with corrosion; lift it a few times in small motions rather than yanking once.
Once the old battery is out, look at the metal contacts inside the holder. If they are green or white, that is corrosion from an old leaking battery. Wipe them clean with a dry cotton swab. Do not use water or rubbing alcohol, which can seep into the movement and cause rust. If corrosion is heavy, you may need a professional watch repair person to clean the movement properly.
Buying and handling the replacement battery
Take the battery code to a pharmacy, watch repair shop, or online retailer. Pharmacies often stock common codes like SR626, SR927, and 371 in their watch battery section. Online retailers have a wider selection and usually cost less, but you will wait for shipping. Do not buy a generic "silver oxide battery" without the code — the wrong size will not fit or will not power the watch correctly.
When you have the new battery, handle it with cotton gloves or tweezers. Skin oils and sweat corrode the metal contacts and reduce battery life. If you touch it with bare fingers, wipe it dry with a clean cloth before inserting it. The battery has two sides: a flat side and a ridged or bumpy side. The flat side always faces up toward the case back; the ridged side faces down toward the movement.
Installing the new battery and closing the case
Slide the new battery into the holder with the flat side up. Make sure it sits flat and does not tilt. Lower the metal clip gently over the battery until it clicks or seats firmly. The clip should hold the battery snug but not so tight that you cannot lift it again if needed. If the clip is very stiff, lift it a few times to loosen it slightly — a clip that is too tight can crack the battery.
Before you close the case back, hold the watch to your ear and listen. You should hear a faint ticking sound. If you hear nothing, the battery may be inserted backwards or the clip may not be making contact. Lift the clip, check that the flat side is facing up, and try again. Once you hear ticking, you can close the case back.
Sealing the case back without stripping the threads
If the case back screws on, hold the watch steady and turn the back clockwise by hand until it is snug. Do not use a tool — hand-tight is correct. If you use a wrench or screwdriver, you risk stripping the threads and damaging the seal. The back should sit flush with the case with no gap around the edge.
If the case back has a slot for a case opener tool, align the slot with the tool and press down gently while turning clockwise. Stop as soon as you feel resistance; do not force it. The back should be snug enough that it does not rattle, but not so tight that you cannot open it again later without the tool.
Testing the watch and troubleshooting common problems
After you close the case, hold the watch to your ear again and listen for ticking. The sound should be steady and regular. If the watch ticks for a few seconds and then stops, the battery may not be making good contact with the clip. Open the case back and check that the clip is pressing firmly on the battery. If the clip is loose, you may need to bend it slightly upward to increase pressure — a very gentle bend, just enough to hold the battery snug.
If the watch still does not tick after you have checked the battery position and clip pressure, the problem may be corrosion on the contacts or a damaged movement. This is the point to take the watch to a professional repair person. Trying to force it or clean the movement yourself can cause more damage.
How long a pocket watch battery lasts
A new pocket watch battery typically lasts one to three years, depending on how often you wind the watch and how much you use it. Some watches have a power reserve that lets them run for a few days without winding; these drain the battery faster. If you wear the watch daily and wind it regularly, the battery may last only a year. If you wind it occasionally and wear it less often, it may last two or three years.
When the battery starts to die, the watch will slow down or stop ticking altogether. You may notice it runs fast for a few days before it stops — this is a sign the battery voltage is dropping. Replace it as soon as you notice the watch slowing down, because a weak battery can damage the movement over time.
Frequently Asked Questions
Can I use a regular alkaline battery instead of a silver oxide battery?
No. Alkaline batteries have a different voltage and shape, and they will not fit the holder or power the watch correctly. Always use the exact code printed on the old battery. Silver oxide batteries are designed for watches and last longer than alkaline in this process.
What if I cannot find the exact battery code?
Take the watch to a jewelry store or watch repair shop and show them the old battery or the inside of the case. They can identify the correct replacement and often have it in stock. Online retailers like Amazon and eBay also let you search by code, and many have detailed product photos showing the battery size.
Is it safe to change the battery myself, or should I go to a professional?
Changing the battery yourself is safe if you work slowly and do not force anything. The main risks are bending the case back or damaging the clip. If you are uncomfortable opening the case or if the clip is stuck, a watch repair person can do it for $10 to $25 and will clean the contacts at the same time.
Why does my watch stop after I close the case back?
The most common reason is that the battery is inserted backwards — the flat side should face up. Open the case, flip the battery, and try again. If that does not work, the clip may not be pressing hard enough on the battery. Lift the clip and check that it is making firm contact with the top of the battery.
Can I leave the case back open while I am testing the watch?
Yes, you can leave it open to listen for ticking and confirm the battery is working. However, do not wear the watch with the case open, because dust and moisture can get inside and damage the movement. Close it as soon as you have confirmed the watch is running.