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

Most pocket watches have a case back that either screws off, pops off with a coin, or requires a special tool to open. The easiest way to find out which type you have is to look at the back of the watch — if you see a slot or notch running around the edge, it unscrews. If the back is smooth with a small lip, it pops off. If there are small notches or a specific pattern, you will need a case opener tool, which costs between $5 and $15 at watch supply shops or online retailers.

To unscrew a case back, place the watch face-down on a soft cloth so you do not scratch it. Use a coin that fits the slot — a dime or penny usually works — and turn counterclockwise slowly. Do not force it; if it does not budge after gentle pressure, the watch may have been sealed at the factory and you should take it to a jeweler instead. For pop-off backs, use a plastic pry tool or the edge of a coin to gently lift the lip around the edge. Work your way around the perimeter rather than prying at one spot, which can bend the case.

Key Takeaways

  • Pocket watch batteries are typically silver oxide or alkaline cells in sizes like SR44, LR44, or 389, and you should note the exact model before buying a replacement.
  • The case back unscrews, pops off, or requires a case opener tool depending on the watch design — check the back for a slot, lip, or notches to determine which.
  • Once open, note how the old battery sits in the compartment and which side faces up before you remove it, so you can install the new one the same way.
  • Most pocket watch batteries cost $3 to $8 and last one to three years depending on how often you wind or use the watch.

Locate and remove the old battery without touching the movement

Once the case back is open, you will see the battery sitting in a compartment, usually held in place by a small metal clip or spring. The battery is a small round cell, typically silver or gold in color. Before you touch anything, take a photo or note exactly how the battery is positioned — which side faces up, how the clip holds it, and where the positive and negative terminals are. This matters because installing a battery backwards will not work and can damage the watch's circuit.

Use a plastic tweezers or a wooden toothpick to gently lift the battery out of its compartment. Avoid touching the metal contacts or the battery terminals with your bare fingers, because skin oils can interfere with the electrical connection. If the battery is stuck, do not pry hard — a gentle rocking motion usually frees it. Once it is out, set it aside and look at the compartment to see if there is any corrosion, which appears as a white or blue-green crust around the contacts. If you see corrosion, clean it with a cotton swab barely dampened with white vinegar, then dry the compartment completely before installing the new battery.

Identify the correct battery size and type before you buy

Pocket watch batteries come in several standard sizes, and using the wrong one will not fit or will not power the watch correctly. The most common sizes are SR44, LR44, 389, 390, and 395. The easiest way to identify which one your watch needs is to look at the old battery itself — the size code is printed on the flat top. Write down the exact code or take a photo of the old battery before you leave the house to buy a replacement.

If the old battery is corroded or the code is worn off, check the watch's instruction manual or contact the manufacturer with the watch model number. You can also take the old battery to a pharmacy, jewelry store, or electronics retailer and ask them to match it by size and shape. Silver oxide batteries (marked SR) last longer and are more stable than alkaline batteries (marked LR), so if you have a choice, silver oxide is worth the slightly higher cost. Expect to pay $3 to $8 for a single battery, depending on the type and where you buy it.

Install the new battery in the same position as the old one

Before you place the new battery in the compartment, check that the contacts are clean and dry. If you cleaned corrosion from the compartment, make sure no vinegar or moisture remains. Using plastic tweezers, hold the new battery and orient it exactly as the old one was positioned — the positive side (usually marked with a + or the flat top) should face the same direction. Gently lower the battery into the compartment and position it so the metal clip or spring holds it in place without forcing it.

The battery should sit flat and find without rocking or shifting. If the clip does not hold it snugly, the watch may not make contact and the battery will not power the movement. Once the battery is seated, do not close the case back yet — first, close the watch face and listen for a ticking sound or check if the second hand moves. If the watch does not start, open the case back again and check that the battery is positioned correctly and making contact with the clip. A quarter-turn adjustment is often all that is needed.

Close the case back securely so moisture does not enter

Once you have confirmed the watch is running, close the case back the same way you opened it. If it screws, turn the coin clockwise until it is snug — do not over-tighten, which can strip the threads or crack the case. If it pops on, press it down evenly around the edge until you hear or feel a click all the way around. A properly sealed case back should feel flush with the case body with no gaps or wobbling.

After closing the case back, wipe the outside of the watch with a soft, dry cloth to remove any fingerprints or dust. Pocket watches are not waterproof even with a sealed case back, so avoid exposing the watch to moisture, humidity, or extreme temperature changes. Store it in a cool, dry place when you are not wearing it. Most pocket watch batteries last one to three years depending on how often you wind or use the watch — if it stops before then, the battery may be defective or the watch may have a deeper electrical problem that a jeweler should examine.

What to do if the case back will not open or the battery will not fit

If the case back is stuck and will not budge after gentle pressure, do not force it further. Forcing a stuck case back can crack the case, strip the threads, or damage the internal movement. Instead, soak the edge of the case back in a small amount of penetrating oil like WD-40 for 10 to 15 minutes, then try again with a coin that has a better grip. If it still will not open, take the watch to a jeweler — they have specialized tools and can open it without damage.

If you have the case open but the new battery does not fit into the compartment, you may have purchased the wrong size. Double-check the code on the old battery or the watch manual. Some older pocket watches use discontinued battery sizes that are no longer made, in which case a jeweler can sometimes adapt a modern battery to fit or recommend a compatible alternative. Do not force a battery into a compartment that is too small, because it can damage the contacts or the case.

Frequently Asked Questions

How do I know if my pocket watch battery is dead or if something else is wrong?

A dead battery is the most common reason a pocket watch stops. If the watch has not run in weeks or months and the second hand does not move when you shake it gently, the battery is likely dead. If the watch ran for only a few weeks after you replaced the battery, the new battery may be defective, the contacts may be dirty, or the watch may have an internal electrical problem that requires professional repair.

Can I use any silver oxide or alkaline battery as long as it is the right size?

Not all batteries of the same size perform identically. Some brands hold a charge longer and are more reliable than others. Stick with well-known brands like Energizer, Duracell, or Panasonic. Avoid very cheap generic batteries, which often have lower capacity and shorter lifespan. If your watch manual specifies a particular battery type, follow that recommendation.

What if I accidentally touched the battery terminals with my fingers?

A brief touch with clean fingers is usually not a problem. If you are concerned, wipe the battery gently with a clean, dry cloth before installing it. Avoid touching the terminals repeatedly or with wet or oily fingers, which can leave a residue that interferes with electrical contact.

Do I need to wind my pocket watch after changing the battery?

No. Pocket watches with batteries do not need winding — the battery powers the movement directly. If your watch is a mechanical wind-up model without a battery compartment, you wind it by hand. If it has a battery, winding does nothing and can damage the mechanism, so do not attempt it.

How long should a pocket watch battery last?

Most pocket watch batteries last between one and three years. The exact lifespan depends on the battery type, the watch's power consumption, and how often you use or wind the watch. Silver oxide batteries typically outlast alkaline ones. If your battery dies much sooner, the watch may have a short circuit or the contacts may be corroded.