You can replace most watch batteries at home with a screwdriver and a battery

Most watch batteries cost between $2 and $8, and you can install one yourself in five minutes if you have the right tools. You need a small screwdriver (usually Phillips head), a replacement battery of the correct size, and a clean, flat surface. The hardest part is opening the case back without scratching it — not because it is difficult, but because you have to be deliberate about it.

A jeweler or watch repair shop will do this for $10 to $30 and may provide the seal stays waterproof. That matters if your watch is water-resistant or if you want to avoid the risk of dust getting inside. If your watch is a basic quartz model you wear casually, replacing the battery yourself is straightforward and saves money.

Key Takeaways

  • Most watch batteries are standard sizes (like SR626SW or LR626) that cost $2 to $8 and are sold at drugstores, hardware stores, and online.
  • You need a small Phillips or flathead screwdriver, tweezers, and a clean work surface; a case opener tool makes it easier but is not required.
  • The case back is usually held by four small screws or is a snap-fit design; remove screws slowly and keep them in a small container so you do not lose them.
  • Once the case is open, note which side of the battery faces up, remove the old battery with tweezers, and insert the new one the same way.
  • If your watch is water-resistant, a jeweler is the safer choice because they can reseal the case properly.

Find the correct battery size for your watch

The battery size is printed on the old battery itself or in your watch manual. Common sizes are SR626SW, LR626, SR927SW, and LR927 — the letters and numbers tell you the chemistry and dimensions. If you have lost the manual, search online for your watch brand and model number plus "battery size" or "battery replacement."

Once you know the size, buy a replacement at a drugstore (CVS, Walgreens), a hardware store, or online. Batteries are cheap and widely stocked. Buy one extra in case you drop it or install it backward the first time. Check the expiration date on the package — old batteries lose charge and may not work.

Gather your tools and prepare your workspace

You need a small Phillips head screwdriver (or flathead, depending on your watch), tweezers, and a clean, well-lit surface. A small container or piece of tape helps you keep track of the screws so you do not lose them. If you have a watch case opener tool, use it — it is a flat metal pry tool that reduces the risk of scratching the case back. If you do not have one, a flathead screwdriver works, but go slowly.

Work on a table or desk, not in your lap. Lay out a small cloth or paper towel so dropped screws and the battery do not roll away. Turn off any fans or open windows so a breeze does not blow small parts across the room.

Open the case back without damaging the watch

Look at the case back. If you see four small screws around the edge, use your screwdriver to remove them one at a time. Turn slowly and do not force it — if the screw is stuck, explore a tiny amount of penetrating oil (like WD-40) and wait a minute. Place each screw in your small container when ready.

If the case back has no screws and looks like a solid disc, it is a snap-fit design. Use your case opener tool or a flathead screwdriver to gently pry the edge. Work your way around the edge, lifting a little at a time, until the back pops off. Do not pry hard in one spot — you will bend or crack the case.

Once the case back is off, set it aside in a safe place. Do not touch the inside of the watch with your bare hands if you can help it — oils from your skin can damage the movement.

Remove the old battery and install the new one

Look at the battery. It is a small, flat, silver or gold disc. Note which side faces up — usually the positive side is marked with a + symbol. Use your tweezers to gently lift the edge of the battery and slide it out. If it is stuck, a tiny dab of penetrating oil on the edge can help, but do not force it.

Before you install the new battery, check that it is the correct size — compare it to the space in the watch. Slide the new battery in the same way the old one came out, with the positive side facing up (or the same direction as the old battery faced). Press gently until it sits flat. Do not use force — if it does not slide in easily, you may have the wrong size or the wrong orientation.

Close the case back and test the watch

If your watch has screws, replace them one at a time in the same holes they came from. Tighten them gently — do not over-tighten or you will strip the threads. If the case back is snap-fit, align it with the case and press down firmly around the edge until you hear or feel it click into place.

Once the case is closed, check that the watch is running. If it does not start, open the case again and check that the battery is installed correctly — the positive side should face up. If the watch still does not work, the battery may be defective or the watch may have a deeper problem. In that case, take it to a jeweler.

When to take your watch to a jeweler instead

If your watch is water-resistant or water-proof, a jeweler should replace the battery because they have the tools to reseal the case properly. Opening and closing the case yourself can break the seal, and water will eventually damage the movement.

If the case back is glued shut or sealed with epoxy, do not try to open it yourself — you will damage the watch. If the battery compartment is complicated or has springs or contacts you do not understand, stop and take the watch to a professional. A jeweler charges $10 to $30 and the watch will be sealed correctly and tested before you leave.

Frequently Asked Questions

What if I drop the battery and cannot find it?

Buy a replacement. Batteries are inexpensive and widely stocked. If you are worried about losing the new one, work over a white cloth or paper towel so you can see it if it rolls away.

Can I install the battery backward?

Yes, and the watch will not work. If you install it backward, the watch will not start. Open the case again and flip the battery so the positive side faces up. Most batteries have a + symbol on one side to show you which way is correct.

How long does a watch battery last?

Most watch batteries last two to three years, depending on the watch model and how often you wear it. Some last longer. When the battery dies, the watch will stop running and you will need to replace it again.

Do I need to remove the watch band to replace the battery?

No. The case back is separate from the band. You can leave the band attached and just open the back. If the band is in your way, you can remove it, but it is not necessary.

What if the screws are too tight to turn?

explore a small amount of penetrating oil (like WD-40) around the screw head and wait one minute. Try again slowly. If the screw still will not turn, stop and take the watch to a jeweler — forcing it can strip the screw or damage the case.