You can change most Timex watch batteries yourself with a case opener and a fresh battery, or take it to a jeweler or Timex service center for $10 to $25
Timex watches fall into two categories: those you can open yourself and those you cannot. Most Timex models sold in the last 20 years have a snap-off caseback — a metal or plastic disc on the rear that pops out with the right tool. A few higher-end or waterproof models have screw-down casebacks that require more care. Before you start, check your watch model number (usually on the back) against Timex's website or your manual to confirm which type you have.
If your watch has a snap caseback, the job takes five minutes and costs $3 to $8 for the battery itself. If it has a screw caseback or you are not confident opening it, a jeweler or Timex service center will do it for you — they have the right tools and can test the seal afterward to make sure water resistance is not compromised.
Key Takeaways
- Most Timex watches have a snap-off caseback that you can open with a plastic case opener tool, available at drugstores or online for $2 to $5.
- You need to know your watch's battery type before you buy a replacement — common sizes are SR626SW, SR927SW, and SR44, and the old battery or your manual will tell you which one.
- Snap casebacks pop straight out with gentle prying; screw casebacks require a case wrench and should be handled by a professional to preserve the waterproof seal.
- After you install the new battery, test the watch to make sure it runs, and wipe the caseback gasket with a dry cloth before closing it to keep moisture out.
Identifying your watch's caseback type
Look at the back of your watch. A snap caseback is a flat or slightly domed disc with a small notch or groove around the edge — it looks like it could pop off. A screw caseback has visible grooves or ridges all the way around, like a jar lid, and requires a wrench to turn it. If you see a tiny screw hole in the center, that is a screw caseback.
If you are unsure, do not force anything. A jeweler can tell you in seconds, and opening a screw caseback the wrong way can crack the crystal or damage the gasket that keeps water out. Timex service centers can also open your watch and change the battery for a flat fee, usually $15 to $25 depending on your location.
What you need to open a snap caseback
You will need a plastic case opener (also called a caseback opener or watch opener) — a small flat tool with a notch designed to fit into the groove on the caseback. Do not use a regular flathead screwdriver; it can slip and scratch the watch. Plastic openers cost $2 to $5 at drugstores, jewelry supply shops, or online retailers like Amazon.
You also need the correct replacement battery. The old battery or your watch manual will show the type — common Timex batteries are SR626SW, SR927SW, SR44, and SR920SW. Buy a fresh battery from a drugstore, pharmacy, or online. Avoid very cheap batteries; a quality silver-oxide battery from Energizer, Duracell, or Panasonic costs $3 to $8 and lasts longer.
Gather a small cloth or paper towel to keep the caseback and gasket clean, and a flat surface where you can work without losing small parts.
Step-by-step: opening the caseback and removing the old battery
Place your watch face-down on a soft cloth so the crystal does not get scratched. Locate the notch or groove on the edge of the caseback — it is usually at the 6 o'clock position (the bottom of the watch when worn).
Insert the plastic opener into the notch and explore gentle, steady pressure — do not pry hard or twist. The caseback should pop out with light pressure. If it does not budge after a few seconds, stop and try a different angle or take it to a jeweler. Forcing it risks cracking the caseback or damaging the gasket underneath.
Once the caseback is off, you will see the battery sitting in a metal holder or compartment. Note which side is facing up (usually the positive side is up). Gently lift or pry out the old battery with the edge of the plastic opener or a plastic spoon — avoid touching the battery with your bare fingers, as skin oils can affect performance.
Installing the new battery and closing the watch
Before you insert the new battery, wipe the gasket (the rubber or plastic ring around the inside of the caseback) with a dry cloth. Any dust or old grease can prevent a watertight seal. Do the same for the metal rim where the gasket sits on the watch body.
Slide the new battery into the holder with the positive side facing up, matching the orientation of the old battery. Press gently until it sits flat. Do not force it; it should rest in place without pressure.
Flip the watch over and check that it is running — you should see the second hand move. If it does not, the battery may not be seated properly. Flip it back over, lift the battery slightly, and reseat it. If the watch still does not run, the battery may be defective; try a fresh one from a different package.
Once the watch is running, align the caseback with the watch body and press straight down until it snaps into place. You should hear or feel a click. Wipe the outside of the caseback with a dry cloth to remove fingerprints.
When to take your watch to a professional
If your watch has a screw caseback, a jeweler or Timex service center should handle the battery change. Screw casebacks require a case wrench to open without damaging the threads, and the gasket needs to be inspected and sometimes resealed to maintain water resistance. A professional will also pressure-test the watch afterward to confirm it is still waterproof.
If your watch is vintage, has sentimental value, or is a high-end Timex model, professional service is worth the cost. You can find a Timex service center through Timex's website, or visit a local jeweler who repairs watches. Most jewelers can change a battery while you wait, and the cost is usually $10 to $25.
Troubleshooting a watch that will not start after a battery change
If the watch does not run after you install the new battery, first check that the battery is seated properly. Remove it, wipe both the battery and the metal contacts inside the watch with a dry cloth, and reseat it. Sometimes dust or corrosion on the contacts prevents a connection.
If the watch still does not run, try a different new battery from a different package — the first one may have been defective. If a second battery does not work, the watch may have a broken contact or a failed circuit, and you should take it to a jeweler for diagnosis.
If the watch runs but stops after a few hours, the battery may not be making full contact. Remove it and check that the metal contacts inside the watch are clean and not bent. If they look corroded or damaged, a jeweler can clean or replace them.
Frequently Asked Questions
Can I use any silver-oxide battery, or does it have to be the exact model number?
The model number matters because it determines the voltage and size. SR626SW, SR927SW, and SR44 are not interchangeable — using the wrong one can damage the circuit or not fit in the holder. Always match the old battery's model number exactly. If you cannot find the model number on the old battery, check your watch manual or contact Timex customer service with your watch model number.
How often do Timex watch batteries need to be changed?
Most Timex watch batteries last two to three years with normal wear. If you wear the watch every day, you may need a new battery sooner. If you wear it occasionally, it may last longer. When the watch slows down or stops, it is time for a fresh battery.
What should I do with the old battery?
Silver-oxide watch batteries contain small amounts of mercury or other metals and should not go in the trash. Most drugstores and battery retailers have a battery recycling bin near the checkout. You can also take old batteries to an electronics recycling center or hazardous waste collection event in your area.
Will opening the caseback myself void the warranty?
If your watch is still under warranty, opening it yourself may void the warranty. Check your warranty card or Timex's website for your model. If the watch is out of warranty, opening it yourself is safe as long as you use the right tool and follow the steps carefully.
Is my watch still waterproof after I change the battery myself?
If you clean the gasket before closing the caseback and snap it firmly into place, the watch should maintain its water resistance. However, snap casebacks are less reliable than screw casebacks for waterproofing. If your watch is rated for swimming or diving, have a jeweler test the seal after you change the battery, or take it to a Timex service center to be sure.