You can change most Timex watch batteries yourself with a coin and steady hands
Most Timex watches use a screw-back case that you can open at home without special tools. The battery itself costs $3 to $8, and the whole job takes about 10 minutes once you have the right battery type. You will need a coin (a dime or penny works), a small flathead screwdriver, the correct replacement battery, and a clean, flat work surface with good light.
The hardest part is not the opening—it is knowing which battery your specific Timex model needs. Timex uses at least a dozen different battery types across their watch lines. Opening the case without the right information can strip the threads or crack the gasket, so start by finding your exact model number before you touch the watch.
Key Takeaways
- Find your Timex model number on the back of the watch case or in your original paperwork, then look up the correct battery type online or call a Timex retailer.
- Use a coin to turn the screw-back case counterclockwise until it comes free; do not force it or you will damage the threads.
- Note the battery orientation (+ side up or down) before you remove the old battery, then install the new one the same way.
- Replace the gasket if it looks cracked or dried out, and screw the case back on hand-tight, then give it one more quarter-turn with a coin.
Find your watch model and the correct battery type
Look at the back of your Timex watch case. You should see a model number printed or engraved there—it usually starts with "T" or a number and is 4 to 8 characters long. Write this down exactly as it appears. If the back is blank or worn smooth, check your original paperwork, warranty card, or the box the watch came in.
Once you have the model number, go to timex.com and use their support section to search for your model, or call a Timex retailer with the number and ask which battery it takes. Common Timex batteries include the SR626SW, SR927SW, SR41, and CR2032, but many models use others. Do not guess—installing the wrong battery can damage the watch or cause it to stop working.
Buy the replacement battery before you open the watch. Most drugstores, supermarkets, and electronics retailers stock common watch batteries for $3 to $8. If your model uses an uncommon battery, order it online so it arrives before you start the job.
Gather your tools and set up your workspace
You need a coin (a dime or penny), a small flathead screwdriver, your new battery, and a clean cloth or paper towel. Lay the cloth on your work surface to catch any small parts and to give you a non-slip surface. Position yourself under a lamp or near a window so you can see the tiny screw and battery clearly.
If your watch has a leather or fabric band, remove it now or tuck it to the side so it does not get in your way. Some Timex bands are glued on; if yours is, leave it attached and just work around it. Have a small container or dish nearby in case you need to set down the screw or old battery—losing either one will stop you cold.
Open the case back without damaging the threads
Hold the watch face-up in your non-dominant hand. Look at the back case—you should see a small slot cut into the edge all the way around, or a single slot at one point. This is where the coin goes. Place your coin (dime or penny) into the slot and turn it counterclockwise (to the left) slowly and steadily.
The case will resist at first. Turn gently but firmly—do not jab or twist hard, or you will strip the slot and make it impossible to open. After a quarter-turn or so, you should feel it loosen. Keep turning until the case back comes free in your hand. If it is stuck after several gentle turns, stop and try a different coin or a coin with a sharper edge; forcing it will damage the watch.
Set the case back down on your cloth, slot-side up, so you know which way it goes back on. Do not lose the screw if your model has one separate piece—some Timex watches have a threaded case back that is all one piece, while others have a removable screw.
Remove the old battery and note its position
Look inside the case. You will see the battery sitting in a small metal holder or contact. Before you touch it, look at which side is facing up—the + (positive) side or the - (negative) side. This matters. Take a photo with your phone if you are not sure you will remember.
Use your fingernail or the edge of your screwdriver to gently pry the battery out of its holder. It should come free with light pressure. If it is stuck, try wiggling it side to side gently rather than prying straight up. Once it is out, set it on your cloth and do not touch the new battery's surfaces with your bare fingers—skin oils can interfere with the electrical contact.
Look at the gasket (the thin rubber or plastic ring around the inside edge of the case back). If it looks cracked, dried out, or flattened, replace it now. Gaskets cost $1 to $3 and prevent water from getting inside the watch. If you are not replacing it, make sure it is still seated properly in its groove.
Install the new battery in the correct direction
Pick up your new battery by its edges only—do not touch the flat surfaces. Orient it so the + side faces the same direction as the old battery did. Gently press it into the holder until it sits flat and makes contact with both the top and bottom contacts inside the case.
The battery should not require force to seat. If it does not sit flush, remove it and check that you have the right battery type and that you are inserting it the correct way. A battery that is not making full contact will not power the watch, and you will think the battery is dead when it is just not seated.
Close the case back and test the watch
Pick up the case back and align the slot with the slot on the watch body. Place your coin in the slot and turn it clockwise (to the right) until the case is snug. Do not over-tighten—one full turn past snug is enough. Over-tightening can crack the gasket or strip the threads.
Once the case is closed, hold the watch to your ear and listen for a ticking sound, or look at the second hand to see if it is moving. If the watch is running, you are done. If it is not, remove the case back again and check that the battery is seated all the way in and oriented correctly. If the battery is correct and seated, the watch may need service from a professional.
Frequently Asked Questions
What if the case back will not open?
Try a different coin with a sharper edge, like a quarter or a dime. If the slot is worn smooth, wrap a rubber band around the coin to improve grip. If it still will not budge after several gentle attempts, stop—forcing it will damage the watch. Take it to a jeweler or Timex retailer instead.
Can I replace the gasket myself?
Yes. Gaskets are inexpensive and come in standard sizes. Remove the old gasket by prying it out gently with a screwdriver, clean the groove with a dry cloth, and press the new gasket into place. Make sure it sits evenly all the way around before you close the case back.
How do I know if I have the right battery?
The battery type is printed on the side of the battery itself. Before you buy, compare the code on your new battery to the code that came up when you searched your model number. If they match, you have the right one.
What if the watch stops working after I put the new battery in?
Remove the case back and check that the battery is seated all the way down and oriented with the + side facing the correct direction. If it is, try a different new battery of the same type—the first one may have been defective. If a second battery does not work, the watch may need professional repair.
Is it safe to open a water-resistant Timex watch?
Yes, but you must replace the gasket every time you open it to maintain water resistance. If your watch is rated for diving or heavy water use, consider having a professional replace the battery instead to may support the seal is perfect.