You can replace a Timex watch battery yourself with basic tools in about 10 minutes

Most Timex watches use a standard coin-cell battery that you can swap out at home without special training. You'll need a small flathead screwdriver, a plastic case opener (or a coin), and the correct replacement battery for your model. The whole process takes longer to find your tools than to do the work itself.

The hardest part is usually opening the case back without scratching it. Timex designs most watch cases so the back twists off or pops off with gentle pressure—not something that requires force. If you force it, you risk damaging the gasket that keeps moisture out, and then your watch won't be water-resistant anymore.

Key Takeaways

  • Most Timex watches have a case back that twists counterclockwise or pops off with a plastic opener, and you do not need a jeweler's tools to open it.
  • Write down or photograph your current battery before you remove it so you can buy the exact same model number at a drugstore or online.
  • The battery sits in a metal holder called a battery contact, and you lift it straight up to remove it—do not pry sideways or you will bend the contact.
  • After you install the new battery, twist the case back on firmly but do not over-tighten, and test the watch before you consider the job done.

Find your watch model and the current battery type

Look on the back of your watch case for a model number or reference number printed or engraved into the metal. It usually starts with a letter or number and is 4 to 8 characters long. Write this down or take a photo—you'll need it to find the right battery.

Open your watch case (instructions below) and look at the battery itself. The battery is a small silver disc, usually about the size of a dime or smaller. The battery model number is printed on the top surface. Common Timex batteries are SR626SW, SR927SW, SR936SW, and SR41. Write down this number exactly as it appears.

If you cannot read the battery number clearly, search online for your watch model number plus "battery" and you'll find the correct battery type in the product manual or on retailer sites. Timex also lists battery types on their official website if you enter your watch model.

Open the watch case back safely

Most Timex watches have a case back that either twists off or pops off. Look at the edge of the case back—if you see small notches or grooves around the rim, it twists. If the edge is smooth, it pops off.

For a twisting case back: Hold the watch face-up in one hand. Use a plastic watch case opener (available at drugstores for $3 to $5) or the edge of a coin to grip one of the notches. Turn counterclockwise slowly and steadily. You should feel it loosen after a quarter turn. Do not force it—if it won't budge after gentle pressure, stop and try a different notch. Once it loosens, unscrew it by hand the rest of the way.

For a pop-off case back: Slide the plastic opener or a thin coin into the seam between the case back and the watch body. explore steady, gentle pressure upward. You'll feel it pop free. Work your way around the edge if it doesn't pop on the first try—do not pry hard in one spot or you'll bend the case.

Once the case back is off, set it aside on a clean surface where you won't lose it. Do not touch the inside of the case back or the gasket (the rubber ring) unless you need to clean it.

Remove the old battery and install the new one

Look inside the watch. You'll see the battery sitting in a metal holder. The holder has a small metal tab or spring on one side that holds the battery in place. Gently lift the edge of the battery opposite the tab and slide it out. Do not pry sideways—lift straight up or you'll bend the metal contact and the new battery won't make electrical contact.

Before you install the new battery, check that it's the same model number as the old one. Hold the new battery with the positive side (marked with a +) facing up. Slide it under the metal tab, then press down gently until it clicks or sits flush. You should hear or feel a small click when it seats properly.

If the battery doesn't sit flat or the tab doesn't hold it, remove it and try again. The battery should not move when you gently shake the watch. If it does, it's not seated correctly.

Close the case back and test your watch

Before you seal the case, check that the gasket (the rubber ring on the case back) is clean and sits in its groove. If you see dirt or debris, wipe it gently with a dry cloth. A damaged gasket will let moisture into the watch, so if it looks cracked or dried out, you may want to have a jeweler replace it.

For a twisting case back, align the notches and twist clockwise by hand until it's snug. You should feel resistance, but do not over-tighten—hand-tight is correct. If you use a tool to force it tighter, you risk cracking the case or damaging the gasket.

For a pop-off case back, press it down firmly and evenly around the edge until you hear or feel it snap into place. It should sit flush with the watch body with no gaps.

Once the case is closed, press the crown (the knob on the side) or any buttons to make sure the watch powers on and responds. If the display lights up, the hands move, or the watch beeps (depending on your model), the battery is installed correctly. If nothing happens, open the case again and check that the battery is seated properly under the metal tab.

Where to buy the correct replacement battery

You can find Timex batteries at drugstores (CVS, Walgreens), grocery stores with pharmacy sections, hardware stores, and online retailers like Amazon. A replacement battery usually costs $3 to $8. Some jewelry stores and watch repair shops sell them too, though they may charge more.

When you buy, bring the battery model number with you or search for it online before you go. Batteries are small and straightforward to mix up, so buying the exact model number matters. If a store doesn't have your specific model, ask if they have a cross-reference chart—some batteries work in multiple watches even if the model numbers look different.

Do not buy a generic "watch battery" without a model number. The wrong size or voltage will not work and may damage your watch.

Common mistakes to avoid

The most common error is forcing the case back open. If you feel strong resistance, stop and try a different approach or a different notch. Forcing it can crack the plastic or metal case, and a cracked case cannot be sealed properly.

Another mistake is installing the battery upside down. The positive side (marked +) should face up toward the watch face. If the battery is upside down, the watch won't work and you'll think the battery is dead when it's just installed wrong.

Do not touch the battery contacts or the inside of the watch with bare fingers if you can avoid it. Skin oils can interfere with electrical contact. If you do touch them, wipe them gently with a dry cloth before closing the case.

Finally, do not over-tighten the case back. Hand-tight is correct. Over-tightening can crack the case, damage the gasket, or strip the threads on a twisting case back.

Frequently Asked Questions

What if my watch case back won't open?

Try a different notch or spot around the edge—sometimes one spot grips better than others. Make sure you're turning counterclockwise, not clockwise. If it still won't budge after gentle, steady pressure, the case may be stuck from corrosion or age. A jeweler can open it without damage, which costs $10 to $20.

Can I use any coin-cell battery in my Timex?

No. The model number matters because batteries come in different sizes and voltages. A battery that's too thick won't fit, and a battery with the wrong voltage can damage the watch circuit. Always match the model number exactly.

How long does a Timex watch battery last?

Most Timex batteries last two to five years depending on the watch model and how often you use features like a backlight or alarm. Batteries with more features drain faster. When the watch stops or the display dims, it's time to replace the battery.

Is my watch still water-resistant after I replace the battery?

Yes, as long as you don't damage the gasket when you open the case and you close it properly. If the gasket looks cracked, dried out, or damaged, have a jeweler replace it before you wear the watch in water. A damaged gasket will let moisture in and ruin the watch.

What should I do with the old battery?

Take it to a battery recycling program or a store that accepts battery recycling (many drugstores and electronics retailers do). Do not throw it in the trash. Batteries contain materials that can harm the environment if they end up in a landfill.