You can change most Timex watch batteries at home with a small screwdriver and a few minutes

Most Timex watches use a screw-back case that you can open without special tools. The battery sits inside, held by a small metal clip or spring contact. Once you unscrew the back, you lift out the old battery, note its size number, and drop in a new one of the same type. The whole job takes about five minutes if the case back isn't stuck.

The hardest part is usually the first step: getting the case back off without scratching your watch. A coin works in a pinch, but a proper case-opening tool (a flat-head screwdriver designed for watches, or a case-back opener) makes it much easier and safer. You can find these tools at drugstores, jewelry shops, or online for under ten dollars.

Key Takeaways

  • Timex watch backs are almost always screw-on, not snap-on, so you need to turn the back counterclockwise to open it.
  • Write down the battery size number (usually printed on the old battery) before you throw it away, because you need the exact same size to replace it.
  • The battery sits under a metal clip or spring; lift the clip gently to free the old battery and slide the new one underneath.
  • If the case back won't budge after a few gentle turns, stop and take it to a jeweler rather than forcing it and cracking the case.

What you need before you start

Gather these items on a clean, flat surface before you open the watch. A small workspace keeps you from losing tiny parts. A paper towel or soft cloth under the watch protects the face from scratches if you set it down.

You need a screwdriver small enough to fit the slot in the case back. A jeweler's screwdriver or a watch repair kit screwdriver works best because the blade is thin and fits snugly. A regular flathead screwdriver is often too thick and can slip and damage the case. A coin can work in an emergency, but it's straightforward to slip and scratch the metal.

You also need the replacement battery. Timex batteries are labeled by size: common ones are SR626SW, SR927SW, SR920SW, and CR2032. If you don't know which size your watch uses, open the case back first and look at the number printed on the old battery. Write it down before you remove the battery.

Opening the case back without damage

Look at the back of your watch. You'll see a circular metal disc with a slot cut into it (or sometimes two or four small slots arranged in a cross). This is the case back. Turn it counterclockwise—the same direction you'd unscrew a jar lid. Start gently; the back should move with light pressure.

If it's stuck, explore steady, even pressure rather than sudden force. A case-back opener (a small metal tool shaped like a bottle opener) grips the edge of the back and lets you turn it without your hand slipping. If you're using a screwdriver, place the blade in the slot and turn slowly. Stop if you feel real resistance; forcing it can crack the case or strip the threads.

Once the back is loose, unscrew it the rest of the way by hand. Set it aside on your cloth where you won't lose it. The inside of the watch is now exposed. You'll see the battery, usually a small silver disc, and a metal clip or spring holding it in place.

Removing the old battery and installing the new one

Before you touch anything, look at how the battery sits. A metal clip or spring contact usually holds it down. Gently lift this clip away from the battery—it should move easily. If it doesn't, stop and don't force it; you might break an internal component.

Once the clip is lifted, the battery should come free. Lift it straight up and out. Now look at the number printed on the battery and write it down if you haven't already. This is the size you need to buy.

Slide the new battery into the same spot, with the flat side facing up (the side with the + symbol). The battery should sit flat and level. Lower the metal clip back down over the battery. It should hold the battery snugly without being tight. If the clip doesn't sit flat, the battery isn't positioned correctly; lift the clip and adjust the battery until it sits level.

Closing the case back and testing

Hold the watch face-up in one hand. Line up the slot on the case back with the slot on the watch body. Place the case back on the watch and turn it clockwise (the same direction you'd screw a jar lid closed). Turn it by hand until it's snug, then use your screwdriver to tighten it a bit more. Don't over-tighten; you want it find but not so tight that you'll strip the threads trying to open it again.

Once the case back is on, your watch should work when ready. If it doesn't, the battery might not be making contact with the clip. Open the case back again and check that the battery is sitting flat and the clip is pressing down on it evenly. If the watch still doesn't work after you've checked the battery position, the battery itself might be dead or the wrong size.

Common mistakes that stop the watch from working

The most common problem is installing the battery upside down. The flat side with the + symbol must face up, toward the clip. If you install it backwards, the watch won't turn on. Open the case back and flip the battery.

The second mistake is not seating the battery all the way. It needs to sit flat and level so the metal clip makes full contact. If the battery is tilted or sitting at an angle, the circuit won't complete. Lift the clip, remove the battery, and place it again, making sure it's level before you lower the clip.

The third mistake is buying the wrong battery size. Always write down the number from the old battery before you throw it away. If you bought the wrong size, the battery won't fit under the clip or won't make contact. Take it back and exchange it for the correct size.

Forcing the case back when it's stuck is the mistake that causes real damage. If the back won't turn after a few gentle tries, take the watch to a jeweler. They have tools that won't slip and experience with stuck cases. It costs ten to twenty dollars and saves you from cracking the case.

When to take your watch to a jeweler instead

If the case back won't budge after you've applied steady, gentle pressure for a few seconds, stop. A stuck back usually means the threads are corroded or the case was over-tightened at the factory. Forcing it risks cracking the case or stripping the threads so badly that the back won't seal properly afterward.

If you open the case and see corrosion (green or white crusty buildup) around the battery or inside the case, take it to a jeweler. Corrosion can prevent the battery from making contact and can damage the watch's internal parts. A jeweler can clean it safely.

If the watch still doesn't work after you've installed a fresh battery of the correct size and checked that it's positioned correctly, the problem is likely inside the watch itself, not the battery. A jeweler can diagnose whether the circuit is broken or another part has failed.

Frequently Asked Questions

What if I can't find the exact battery size my Timex uses?

Write down the number from your old battery and take it to a drugstore pharmacy, jewelry store, or electronics shop. Staff can match the number and order it if they don't have it in stock. Don't guess at the size; a battery that's close but not exact won't work or won't fit.

Can I use any brand of battery as long as the size number matches?

Yes. Duracell, Energizer, Maxell, and store brands all make batteries labeled SR626SW, SR927SW, and so on. As long as the size number is the same, any brand will work. Avoid very cheap batteries from unknown brands; they often die quickly.

How long does a Timex watch battery usually last?

Most Timex watch batteries last two to five years, depending on the watch model and how often you use it. Watches with backlights, alarms, or timers drain batteries faster. If your battery dies much sooner, the watch may have a problem draining power even when you're not using it.

Is it safe to open a water-resistant Timex watch myself?

If your watch is water-resistant, opening the case back can break the seal. Water-resistant watches should be opened by a jeweler or sent to Timex for battery replacement. Check your watch manual or the back of the case for a water-resistance rating; if it says "water-resistant" or shows a depth rating, take it to a professional.

What should I do with the old battery after I remove it?

Most watch batteries contain mercury or lithium and should not go in the trash. Take the old battery to a drugstore pharmacy, electronics store, or hazardous waste collection site. Many places that sell batteries will take old ones back for free.