You can change most watch batteries yourself with a case opener and a fresh battery
Replacing a wristwatch battery is a task you can do at home with the right tools and a steady hand. Most quartz watches use a standard coin-cell battery that costs between $3 and $15, and the job takes 10 to 20 minutes once you have what you need. The hardest part is opening the case back without scratching it — everything else is straightforward.
If your watch is waterproof, sealed, or has a screw-down case back, a jeweler or watch repair shop is the safer choice. They have the equipment to reseal it properly and keep water out. But for a standard snap-back case, the process is straightforward enough that most people can do it.
Key Takeaways
- You need a case opener tool, a fresh battery in the correct size, and tweezers or a small screwdriver to remove the old battery safely.
- Find your watch's battery size by checking the case back, the instruction manual, or removing the old battery and reading the number printed on it.
- A case opener tool costs $5 to $20 and is the only tool most people don't already own — tweezers and a small screwdriver work for the rest.
- If you slip with the case opener and scratch the case back, the watch will still work, but the cosmetic damage is permanent.
- Waterproof watches and those with screw-down case backs should go to a jeweler, because resealing them requires tools and informed you won't have at home.
Find out what battery size your watch uses
The battery size is printed on the old battery itself, so the easiest way is to open the case and look. Battery codes are usually three or four characters — SR626, CR2032, LR44, and AG13 are common examples. The first letters tell you the chemistry (silver oxide, lithium, alkaline), and the numbers tell you the physical size.
If you haven't opened the case yet, check the instruction manual or the case back itself — some watches print the battery type there. If neither of those works, search online for your watch brand and model plus the word "battery." You will find the size in the first few results.
Once you know the size, buy a fresh battery from a pharmacy, electronics store, or online. Avoid the cheapest option — a mid-range battery from a known brand (Energizer, Panasonic, Renata) will last longer and cost only a dollar or two more.
Gather the tools you need
You need three things: a case opener, tweezers, and the new battery. A case opener is a small flat tool with notches that fit into the grooves on the case back. It costs $5 to $20 and is the only tool most people have to buy. You can find them at watch repair shops, jewelry stores, or online retailers.
For tweezers, any fine-point tweezers will work — the kind used for eyebrows or electronics work. A small flathead screwdriver (the kind in a basic toolkit) can also remove the battery if you don't have tweezers. Do not use your fingers to handle the battery, because skin oils can shorten its life.
Lay everything on a clean, flat surface with good light. A small bowl or tray keeps parts from rolling away. If your watch has a leather strap, remove it first so you don't get scratched or damage the strap while you work.
Open the case back without scratching it
Look at the case back and find the notches or grooves — they are usually small indents spaced around the edge. Insert the case opener into one of the notches and explore gentle, steady pressure to rotate it counterclockwise. The case back should pop off after a quarter turn or less. If it doesn't move, try a different notch — sometimes one notch is easier than others.
The most common mistake is using too much force. If you feel strong resistance, stop and try a different notch instead of pushing harder. Pushing too hard will slip the tool and scratch the case back. Once the case back is loose, you can usually lift it off by hand.
Set the case back aside on a clean surface where it won't get scratched or lost. The inside of the watch is now exposed — you will see the battery sitting in a metal holder, usually held in place by a small metal clip or spring.
Remove the old battery and install the new one
Use tweezers or a small screwdriver to gently lift the metal clip or spring that holds the battery in place. The battery will come free — lift it straight out and set it aside. Do not touch the top or bottom of the new battery with your bare fingers. Hold it by the edges only.
Slide the new battery into the holder with the positive side (usually marked with a + or the shiny side) facing up. Lower the metal clip back down over the battery until it clicks or sits flush. The battery should not move or rattle — if it does, the clip is not seated properly.
Before you close the case, press the crown (the knob on the side of the watch) a few times to make sure the watch is working. You should hear a ticking sound or feel a vibration. If nothing happens, the battery may be installed upside down — flip it and try again.
Close the case back and test the watch
Align the case back with the case and press it down firmly. You should hear or feel a small click as it snaps into place. If it doesn't snap, the battery may be sticking up too high — open the case again and make sure the battery is seated all the way down in the holder.
Once the case back is closed, set the watch on a flat surface and listen for ticking. If it ticks, the battery is working. If it doesn't, open the case again and check that the battery is the right way up and fully seated. If the watch still doesn't work after that, the battery may be defective — try a fresh one from a different package.
Wipe the case back with a soft, dry cloth to remove fingerprints and dust. Your watch is now ready to wear. Most standard batteries last two to three years before the watch stops again.
When to take your watch to a jeweler instead
If your watch has a screw-down case back (one with a threaded edge that twists on and off), do not try to open it yourself. The threads are delicate and straightforward to strip, and you need a special tool to open it without damage. A jeweler has that tool and can reseal it properly.
If your watch is marked waterproof or water-resistant, opening it at home breaks the seal. A jeweler can replace the battery and reseal it with a new gasket to restore the waterproofing. Doing it yourself will let water into the movement and ruin the watch over time.
If the case back is glued on instead of snapped on, trying to pry it open will crack it. This is rare in modern watches, but if you see no grooves or notches, stop and take it to a professional. The cost of a battery replacement at a jeweler is usually $10 to $25, which is worth it to avoid breaking your watch.
Frequently Asked Questions
Can I use any battery that fits, or does it have to be the exact size?
It has to be the exact size. Using a battery that is too large can jam the case back or damage the movement. Using one that is too small will rattle and may not make proper contact. Always match the code on the old battery or in the manual.
What if the case back won't open no matter what I do?
Stop trying. You may be using the wrong tool, the case back may be glued, or the notches may be stripped. Take it to a jeweler rather than risk cracking the case or damaging the movement. A professional can usually open it in minutes.
How long does a watch battery last after you put it in?
Most standard watch batteries last two to three years of normal wear. Some last longer, some shorter, depending on the watch model and how often you wear it. Batteries in watches you wear every day tend to last longer than those in watches worn occasionally.
Do I need to do anything special to store the old battery?
Old watch batteries are safe to throw in the trash in most places. If your area has a battery recycling program, you can drop it off there instead. Do not leave it where children or pets can swallow it — button batteries can cause serious injury if ingested.
Will changing the battery myself void the warranty?
Most watch warranties do not cover battery replacement, so changing it yourself will not void anything. However, if your watch is still under warranty and you damage the case or movement while opening it, the manufacturer may refuse to repair it. If you are unsure, contact the manufacturer before you open the case.