Change a watch battery yourself – step-by-step guide

What do you need to change a watch battery?

Before you start, you'll need three things: a new battery that fits your watch model, a tool to open the case back, and tweezers to handle the battery. You should never touch the battery with bare fingers – skin oils can damage contact surfaces in the movement.

• New watch battery – the most common types are SR626SW, SR621SW, and CR2032. The battery type is embossed on the old battery or found in the watch's manual.
• Case opener (case knife) – for snap-on case backs, or a screw tool for screw-down case backs. A thin kitchen knife can work for snap-on case backs but risks scratching the watch.
• Anti-static tweezers – to carefully remove and insert the battery without static discharge.
• Soft cloth – to place the watch on so the crystal doesn't get scratched.

You can buy watch batteries in grocery stores, electronics stores, and online. If you want to avoid buying the wrong battery: remove the old battery first and bring it with you when you shop.

How do you know which battery fits your watch?

The battery type is usually embossed on the old battery once you've opened the watch. Alternatively, the information can be found in the watch's accompanying manual or from the watch manufacturer's support. The most common batteries in wristwatches are silver oxide batteries (SR series) and lithium coin cells (CR series). Don't confuse the sizes – a battery that is half a millimeter too thick can damage the movement.

How to change the battery – step by step

Follow the steps in order. Take your time and work on a clean, well-lit surface.

1. Identify the case back type

   There are three common types of watch case backs:

   • Snap-on case back – the most common. The back is pressed into place and pried open with a case knife along the edge.
   • Screw-down case back – the back is unscrewed clockwise. Often used on more robust sports and dive watches.
   • Screw-on case back with screws – four to six visible screws on the back. Requires the correct screwdriver size.

   Look at the back of the watch. If you see a smooth edge without screws, it's likely a snap-on case back. If you see a grooved fitting around the edge, it's a screw-down case back.

2. Clean the watch and ground yourself

   Clean the exterior of the watch with a soft cloth before opening it, so that dirt doesn't get inside the movement. Then, ground yourself by touching a metal object connected to the ground, such as a radiator or a metal faucet. This neutralizes static electricity that could otherwise damage the watch's electronics.

3. Open the case back

   Place the watch on the soft cloth with the crystal face down. Find a small notch on the edge of the case back (snap-on case back). Insert the tip of the case knife into the notch and pry open the back with gentle but firm pressure. Keep a finger on the back so it doesn't fly off.

   For a screw-down case back: unscrew counter-clockwise with the case tool or a screwdriver of the correct size. Press down lightly while screwing to avoid slipping and scratching the watch.

   Note: If the watch is water-resistant, there is a rubber gasket inside the case back. Make sure it doesn't get stuck or disappear when you open it. Set it aside on a clean surface.

4. Remove the old battery

   Use tweezers to carefully lift out the old battery. Note which way it is oriented – the positive side (+) should normally be facing upwards. Many battery holders have a small tab or clip that holds the battery; gently pry if that's the case. Never touch other parts of the movement.

   Now check the battery designation, for example, SR626SW, and set the battery aside to read the embossed text.

5. Insert the new battery

   Place the new battery with the correct side up (+ upwards, unless otherwise specified). Gently press it down with the tweezers until it snaps into place in the holder. Avoid pressing hard – it should only require light pressure. Immediately check if the second hand starts moving; if it does, the battery is working and the contact is good.

6. Replace the rubber gasket (if water-resistant watch)

   If the watch has a rubber gasket: check that it is intact and not damaged. Place it back into its groove in the case back before closing. A damaged gasket means the watch is no longer water-resistant – how much water it can withstand is related to its water resistance (ATM). Replace the gasket or have a watchmaker do it before exposing the watch to water.

7. Close the case back

   Snap-on case back: place the back into position and press evenly with your thumb around the entire edge until you hear a click. Check that there is no visible gap around the edge. Screw-down case back: screw clockwise and tighten without overtightening – it shouldn't require more force than finger pressure. Then set the time and date if the watch reset during the battery change.

When should you take your watch to a watchmaker instead?

Not all watches are suitable for at-home battery changes. Take your watch in if any of the following apply: it has high water resistance and is intended for swimming or diving, the gasket is worn or difficult to reposition, the case back is extremely tight, or if it is a more expensive or older watch with a delicate movement. If you have a watch with high water resistance – for example, a dive watch – the gasket should be checked by a watchmaker afterwards, otherwise you risk water ingress.

Do you have a quartz watch that needs a new battery?

Most quartz watches are designed for at-home battery changes. If you are unsure whether your particular watch is suitable for this – for example, if it has deeper water resistance or a more delicate movement – it might be worth letting a watchmaker do the job. Feel free to read our guide on when you need a battery change versus service if you want help deciding.

Want to avoid battery changes altogether? Automatic watches are powered by kinetic energy and never need a battery.

Can I change the battery on any watch at home?

Most simpler quartz watches with snap-on or screw-down case backs can be changed at home. Watches with high water resistance (100 meters or more), mechanical watches that need adjustment afterwards, or watches with screws that require special tools should be taken to a watchmaker to avoid damage.

How do I know which battery fits my watch?

The battery type is embossed on the old battery once you open the watch. It may also be in the watch's manual. Common designations are SR626SW, SR621SW, and CR2032. Bring the old battery with you when you shop to avoid buying the wrong size.

What happens if I accidentally touch the movement with my fingers?

Skin oils can cause corrosion on contact surfaces and delicate parts in the movement. If you accidentally touch something: gently wipe with a soft, dry cloth. Always use tweezers to handle the battery and avoid touching more of the movement than necessary.

Does the watch lose time or date when I change the battery?

Yes, the watch often resets during a battery change. Set the time and date immediately after closing the case back and checking that the second hand is moving. Some watches save settings for a short time thanks to a capacitor, but expect to need to reset.

How often does a watch battery need to be changed?

Most quartz watches need a new battery every two to five years depending on the watch type, how often backlighting and alarm are used, and the battery's capacity. Watches with illuminated displays, alarms, and pedometers drain the battery faster.

Does the watch lose water resistance when you change the battery at home?

That depends on whether the rubber gasket is intact and correctly installed. If the gasket is intact and replaced correctly, the watch will maintain its water resistance with normal use. Watches with higher water resistance (100 meters and above) should be tested by a watchmaker after a battery change if you plan to swim or dive with them.