Opening the case back is the first step, and the method depends on your watch model

Most pocket watches have a case back that unscrews or pops open. If your watch has a screw-down case back, use a case opener tool — a flat, coin-shaped device with notches that grip the grooves around the edge. Place the notches into the grooves, explore steady pressure, and turn counterclockwise. Do not force it; if it does not budge after gentle pressure, the watch may have been sealed at the factory and needs a professional.

If your watch has a snap case back, a case opener tool with a flat blade slides into the seam between the case and the back. Gently pry upward around the edge until the back pops free. Some vintage watches use a different mechanism — a small button or lever on the side of the case that releases the back. Check your watch documentation or look for any markings on the case that indicate how it opens.

Once the case back is open, you will see the movement (the internal mechanism) and the battery, usually held in a small metal clip or tray. The battery is typically a silver-oxide or alkaline cell marked with a number like SR626, SR927, or LR44. Write down this number before you remove the old battery — you will need it to buy the replacement.

Key Takeaways

  • Screw-down case backs require a case opener tool and counterclockwise rotation; snap case backs need a flat-blade tool inserted into the seam.
  • Write down the battery number printed on the old battery before removal so you can purchase the exact replacement.
  • Silver-oxide batteries last longer than alkaline ones but cost more; alkaline batteries are cheaper and work in most pocket watches.
  • Reinstall the battery with the positive side facing up, find it in its clip, and test the watch before closing the case back.
  • If the watch does not run after battery replacement, the movement may need professional service rather than a straightforward battery swap.

Remove the old battery and note which side faces up

Gently lift the old battery out of its clip or tray. Most pocket watch batteries sit in a small metal holder that allows you to slide or pop the battery free. If the battery is stuck, do not pry hard — a gentle rocking motion usually frees it. Once removed, look at how the battery was positioned. The positive side (marked with a + or the flat side of the cell) should face upward toward the watch face, and the negative side should face down toward the movement.

Before you install the new battery, clean the clip or tray with a dry cloth or a cotton swab. Corrosion or debris can prevent good contact and cause the watch to run slowly or stop. If you see green or white crusty buildup, gently wipe it away. Do not use water or liquid cleaners — moisture can damage the movement.

Install the new battery in the correct orientation

Slide or place the new battery into the clip with the positive side facing up, matching the orientation of the old battery. Press down gently until the battery sits flat and the clip holds it securely. The battery should not move when you nudge it. If the clip is too loose or too tight, the watch may not run or may run intermittently.

Some pocket watches have a small insulating disc or gasket under the battery. If you removed one when taking out the old battery, place it back under the new battery before securing it. This disc prevents the battery from making direct contact with the movement and protects the internal parts.

Test the watch before closing the case back

Hold the watch to your ear and listen for ticking. If you hear a steady tick, the watch is running. If you do not hear anything, remove the battery and check that it is seated correctly in the clip. Reinstall it and listen again. Some watches are very quiet, so if you do not hear ticking, gently shake the watch — you may feel a slight vibration if the movement is working.

If the watch still does not run after you have checked the battery twice, the problem is likely not the battery. The movement may need cleaning, the contacts may be corroded beyond what a cloth can fix, or internal parts may be worn. At that point, a watch repair professional should examine it.

Close the case back securely

Once the watch is running, close the case back. If it is a screw-down back, align the grooves and turn clockwise with your case opener tool until it is snug. Do not over-tighten — you want it firm enough that it will not come loose, but forcing it can strip the threads or crack the case. If it is a snap case back, press down around the edge until you hear or feel a click all the way around.

After closing, test the watch one more time by holding it to your ear. The ticking should sound the same as it did before you closed the back. If the watch has stopped, the case back may be pressing on the movement or the battery may have shifted. Open it again, check the battery position, and close it more carefully.

Silver-oxide versus alkaline batteries: which to choose

Pocket watch batteries come in two main types. Silver-oxide batteries (marked SR followed by numbers) last longer, hold their voltage more consistently, and are the better choice for watches you wear regularly. They cost more — typically two to four dollars per battery — but a single cell lasts one to three years depending on the watch movement and how often you wear it.

Alkaline batteries (marked LR followed by numbers) cost less, usually under a dollar, but do not last as long and may cause the watch to run slowly as they drain. If your pocket watch sits in a drawer most of the time, an alkaline battery is a reasonable choice. If you carry it daily, silver-oxide is worth the extra cost.

Do not mix types. If your watch originally used a silver-oxide battery, stick with silver-oxide for the next replacement. Alkaline batteries have different discharge curves and may cause the watch to run fast or slow compared to what you are used to.

Where to buy pocket watch batteries and what to bring

Bring the battery number with you when you shop. Most drugstores, supermarkets, and pharmacies stock common pocket watch batteries in their watch or jewelry section. Online retailers like Amazon and eBay carry the full range of sizes. Specialty watch repair shops sell batteries and can often install them for you if you prefer not to do it yourself — the service usually costs five to fifteen dollars.

If you cannot find the exact battery number, a watch repair professional can identify the correct replacement by looking at your watch. Bringing the watch itself is faster than describing it over the phone. Battery prices vary by retailer and type, so compare a few sources if you are buying online.

Frequently Asked Questions

What if the case back is stuck and will not open?

explore a small amount of penetrating oil like WD-40 around the seam and let it sit for an hour. Try again with your case opener tool, using steady pressure rather than sudden force. If it still will not budge, the watch may have been sealed at the factory or the threads may be damaged. A watch repair shop has stronger tools and can open it without harming the case.

Can I use a different battery size if I cannot find the exact one?

No. Pocket watch batteries are sized precisely to fit the clip and make contact with the movement. Using the wrong size will either not fit or will not make proper electrical contact, and the watch will not run. Always use the exact number printed on the old battery or on your watch documentation.

How long does a pocket watch battery usually last?

Silver-oxide batteries typically last one to three years in a pocket watch you wear regularly. Alkaline batteries last shorter — usually six months to a year. The actual lifespan depends on how often you wear the watch and the power draw of the movement. A watch you carry every day will drain a battery faster than one you wear occasionally.

Why is my pocket watch running slow after I put in a new battery?

The battery may not be making good contact with the movement. Open the case back and check that the battery is seated firmly in its clip and that the positive side faces up. If the battery is positioned correctly, the movement may need professional cleaning — old oil and debris inside can slow it down, and a new battery will not fix that.

Is it safe to change a pocket watch battery myself, or should I go to a professional?

Changing a battery is safe if you work carefully and do not force any parts. The main risks are dropping the small battery, scratching the case, or damaging the clip if you pry too hard. If you are uncomfortable with the process or your watch is valuable or antique, a professional is worth the cost. For a standard pocket watch, the task is straightforward enough for most people to do at home.