You can change most Timex watch batteries at home with a case opener and a fresh battery

Most Timex watches use a snap-off or screw-off case back that you can open without special tools beyond a coin or a plastic case opener. Once the back is off, you lift out the old battery, note its size number, and drop in a new one of the same type. The whole job takes five minutes. Some Timex models — particularly dive watches and chronographs — have sealed cases that require a jeweler or watch repair shop to open safely, so check your manual first.

The battery size matters. Timex watches commonly use SR626SW, SR927SW, SR936SW, or CR2032 batteries, depending on the model. You can find these at drugstores, supermarkets, electronics retailers, or online for between $3 and $8. Buy the exact replacement your watch currently holds, or check your Timex manual for the correct part number.

Key Takeaways

  • Most Timex watches have a snap-off or screw-off case back that opens with a coin or plastic opener, not a jeweler's tool.
  • Write down the battery size printed on the old battery before you remove it, or check your Timex manual for the correct replacement number.
  • Batteries cost $3 to $8 and are sold at drugstores, supermarkets, and electronics stores under their part number (SR626SW, SR927SW, SR936SW, or CR2032 are common).
  • Sealed Timex models like dive watches and some chronographs cannot be opened safely at home and need a professional jeweler or Timex service center.

Identify your Timex model and case type

Check the back of your watch. If you see a thin line running around the edge of the case back, it is a snap-off case. If you see a groove or notch around the edge, it is a screw-off case. If the case back is completely smooth with no seam, your watch is sealed and should not be opened at home.

Look for any text printed on the case back. Timex often stamps the model number and sometimes the battery size directly on the back. If you see a battery code like SR626SW or CR2032, write it down — that is the exact replacement you need. If you cannot read the printing clearly, check your watch manual or the Timex website by model number.

Gather the right tools and battery

For a snap-off case, you need a plastic case opener (sold at watch repair shops and online for $2 to $5) or a coin with a thin edge. A dime or penny works. For a screw-off case, you need the same tools plus a small flathead screwdriver that fits the groove without slipping.

Before you open the watch, buy the replacement battery. Take the old battery to a drugstore or electronics store and ask for the same size, or order it online by the part number. Keep the old battery in your pocket until you have the new one in hand — if something goes wrong, you can put the old one back in and the watch will work again.

Open a snap-off case back

Hold the watch face-up in one hand. Locate the thin seam around the edge of the case back. Insert the edge of your plastic opener or coin into the seam at the point closest to you. Push gently but firmly — the back should pop off with a small click. If it does not move, try a different spot on the seam; sometimes one side is easier than another.

Once the back is loose, use your fingernail or the opener to pry it the rest of the way off. Set it aside on a clean surface. Do not lose it — you will need to snap it back on when you are done.

Open a screw-off case back

Hold the watch face-up. Locate the small groove or notch around the edge of the case back. Insert your flathead screwdriver into the groove and turn it counterclockwise (to the left) slowly. After one or two full turns, the back will loosen enough to unscrew by hand. Finish unscrewing it with your fingers and set it aside.

If the screwdriver slips or the groove is too tight, try a slightly smaller screwdriver or wrap a thin rubber band around the screwdriver tip for grip. Do not force it — forcing a stuck screw-off back can strip the groove and make it impossible to open again.

Remove the old battery and install the new one

Look inside the case. You will see the battery sitting in a small metal holder or clip. The battery is usually round and silver or gold. Gently lift one edge of the battery with your fingernail or a plastic tool to pop it out of the holder. If it is held by a metal clip on one side, lift the clip first, then slide the battery out.

Before you throw away the old battery, check the number stamped on it one more time. Make sure your new battery matches. Drop the new battery into the holder with the positive side (usually marked with a + or the shiny side) facing up. Press gently until it clicks into place. The battery should sit flat and not rock.

Close the case back and test the watch

For a snap-off case, align the case back with the watch body so the seam lines up evenly all the way around. Press down firmly and evenly around the edge until you hear a click and feel it seat. The back should be flush with the case when it is closed.

For a screw-off case, thread the back on by hand first to make sure it is going straight. Once it is hand-tight, use your screwdriver to turn it clockwise (to the right) until it is snug. Do not over-tighten — snug is enough.

Check that your watch is running. If it is not, open the case again and make sure the battery is seated properly and facing the right direction. If the watch still does not work after you reseat the battery, the old battery may have been dead for a long time and the watch may need a professional check, or you may have installed the wrong battery size by mistake.

When to take your Timex to a professional

If your watch has a sealed case back with no seam or groove, do not try to open it. Sealed cases are glued or welded shut and opening one at home will damage the watch. Take it to a Timex service center or a jeweler who repairs watches.

If you open the case and the battery holder is corroded, cracked, or damaged, or if you see water inside the case, stop and take the watch to a professional. Water inside means the seal is broken and the watch needs service before you can safely use it again. If the watch still does not work after you install a fresh battery of the correct size, the movement may need repair.

Frequently Asked Questions

What if I cannot get the case back off?

Try a different spot on the seam — some watches open more easily on one side. For a snap-off, use a plastic opener instead of a coin; it grips better. For a screw-off, wrap a rubber band around the screwdriver tip for grip, or try a slightly smaller screwdriver. If it still will not budge after a few gentle tries, take it to a jeweler rather than risk damaging the case.

How do I know which battery size to buy?

Check the case back of your watch for a printed battery code like SR626SW or CR2032. If you cannot read it, check your Timex manual or look up your model number on the Timex website. You can also take the old battery to a drugstore and ask for the same size. Never guess — the wrong size will not fit or will not power the watch.

Can I use a different brand of battery as long as it is the same size?

Yes. Duracell, Energizer, Timex, and store brands all make the same battery sizes. The part number matters more than the brand — an SR626SW from any maker will work in any watch that takes an SR626SW.

What should I do if water is inside the case when I open it?

Close the case back when ready and take the watch to a jeweler or Timex service center. Water inside means the seal is broken. Continuing to wear the watch will damage the movement. A professional can dry it out and replace the seal.

How long does a Timex watch battery last?

Most Timex batteries last two to three years with normal wear. Batteries in watches you wear every day may last longer than batteries in watches you wear occasionally. If your battery dies much sooner, the watch may have a power drain or the battery holder may be corroded.