How Do You Change a Watch Battery with a Screw Back?

AvatarByArmando Lewellen Usage Guides

Changing the battery in a watch with a screw back may seem like a daunting task, especially if you’re used to simple snap-on cases or have never opened a watch before. However, with the right approach and a bit of patience, it’s entirely possible to do it yourself without needing to visit a professional. Understanding the basics of how these screw back cases function is the first step toward mastering this handy skill.

Watches with screw back cases are designed to provide a secure, tight seal that protects the delicate internal components from dust, moisture, and other external elements. This design, while effective, requires a specific technique and tools to open safely without damaging the watch. Whether your watch is a prized heirloom or a daily accessory, knowing how to properly access and replace its battery can save you time and money, and give you a satisfying sense of accomplishment.

In the following sections, you’ll discover the essential tips and considerations for handling screw back watches, from identifying the right tools to understanding the careful steps involved in removing and replacing the battery. By the end of this guide, you’ll be equipped with the knowledge to confidently maintain your watch’s power and keep it ticking smoothly.

Tools and Materials Needed for Removing a Screw Back Watch

To successfully remove the screw back of a watch and replace its battery, having the right tools is essential. Using improper equipment can damage the watch case or compromise its water resistance. The primary tools you will need include:

  • Case back opener wrench or a specialized screw back case opener
  • Precision screwdrivers
  • Tweezers (preferably non-magnetic)
  • Case holder or a soft cloth to stabilize the watch
  • Dust blower or a soft brush for cleaning
  • Replacement battery compatible with your watch model
  • Plastic prying tool or a small flat tool for battery removal

Each of these tools plays a crucial role in ensuring the watch is opened carefully and the battery is replaced without causing damage.

Steps to Safely Open a Screw Back Watch Case

Begin by placing the watch face down on a soft, clean surface or in a case holder to prevent scratches and movement. Identify the notches or grooves on the screw back case, which are designed for the case back opener wrench. Adjust the wrench pins to fit these grooves precisely.

Gently apply pressure while turning the wrench counterclockwise to unscrew the back. If the case back is tightly secured, avoid excessive force to prevent slipping or damage. Instead, apply steady, moderate pressure and ensure the wrench is firmly seated.

Once the back is loosened, carefully lift it away from the case. Avoid touching the internal components with bare fingers to prevent contamination.

Handling the Watch Battery and Internal Components

Before touching the battery, use plastic tweezers to avoid short-circuiting or discharging the battery. Note the orientation of the battery, including which side is facing up, as this is critical for proper installation.

If the battery is held in place by a clip or screw, use an appropriate precision screwdriver to remove it. Place all screws and small components safely to avoid loss.

Clean the battery compartment gently with a dust blower or a soft brush to remove any debris or dust particles. This helps maintain good contact and prolong battery life.

Choosing the Correct Replacement Battery

Selecting the correct battery type is vital for the watch’s functionality. Watch batteries vary in size, chemistry, and voltage. Refer to the watch manual or the existing battery for specifications.

Common types include silver oxide and lithium batteries, with voltages typically around 1.5V or 3V. Using an incompatible battery can cause malfunction or damage.

Battery Type Common Sizes Voltage Typical Use Cases
Silver Oxide SR626SW, SR621SW, SR920SW 1.55V Analog watches, quartz watches
Lithium CR2025, CR2032, CR2450 3V Digital watches, watches with additional functions
Alkaline LR626, LR621 1.5V Budget watches, some older models

Always verify the battery model number printed on the battery or in the watch manual to ensure compatibility.

Replacing the Battery and Securing the Case Back

After removing the old battery, insert the new battery in the exact same orientation. Ensure the battery sits flush and makes proper contact with the terminals.

If applicable, reattach any clips or screws that secure the battery. Double-check that no dust or debris is inside the watch before closing the case back.

Align the screw back with the threads on the watch case carefully. Using the case back wrench, turn it clockwise to tighten. It should be secure but avoid over-tightening to prevent stripping the threads or damaging the gasket.

If the watch includes a gasket or seal, inspect it for wear and replace it if necessary to maintain water resistance.

Precautions and Tips for Maintaining Watch Integrity

  • Work in a clean, dust-free environment to prevent contamination inside the watch.
  • Use non-magnetic tools to avoid interference with the watch’s movement.
  • Avoid touching the battery terminals or internal parts with your fingers.
  • If unsure about the battery type or watch mechanism, consult a professional.
  • Regularly check the watch’s water resistance after battery replacement, especially if used in aquatic environments.

By following these detailed steps and using appropriate tools, you can safely and efficiently change the battery of a screw back watch without compromising its performance or durability.

Tools and Materials Needed to Change a Screw Back Watch Battery

Changing the battery of a screw back watch requires specific tools to ensure the process is done safely and correctly. Using inappropriate tools can damage the watch case or internal components.

  • Watch Case Opener Tool: A specialized tool designed to unscrew the back cover of the watch. Variants include adjustable case wrenches or case back openers with multiple prongs.
  • Non-Magnetic Tweezers: To handle the battery safely without causing short circuits or damage.
  • Small Screwdrivers: Precision screwdrivers (typically Phillips or flathead) may be needed to remove battery holders or clamps inside the watch.
  • Plastic or Wooden Stick: To gently pry or maneuver components without scratching.
  • Replacement Battery: Confirm the exact battery model (usually printed on the old battery) before purchasing a new one.
  • Soft Cloth or Pad: To place the watch on during the process to avoid scratches.
  • Magnifying Glass or Loupe: To closely inspect small components and ensure proper placement.

Preparing the Watch for Battery Replacement

Proper preparation minimizes the risk of damage and ensures a smooth battery replacement process.

  • Work in a clean, well-lit area free from dust and static electricity.
  • Place a soft cloth or pad on the work surface to prevent scratches on the watch.
  • Remove any bracelets or straps if they obstruct access to the case back.
  • Ensure the watch is completely dry and free of moisture.
  • Identify the type of screw back case by examining the back cover for notches or grooves.
  • Confirm the battery type by noting the model number printed on the battery or in the watch manual.

Opening the Screw Back Case Safely

Opening the screw back case requires patience and the correct technique to avoid damaging the watch or its gasket, which ensures water resistance.

  • Secure the Watch: Place the watch face down on the soft cloth or pad to protect the crystal.
  • Adjust the Case Opener: Fit the watch case opener prongs into the notches or grooves on the back of the watch.
  • Apply Controlled Pressure: Turn the opener counterclockwise slowly with steady pressure to unscrew the back cover.
  • Inspect the Gasket: Once opened, check the rubber gasket for any cracks or damage; replace if necessary to maintain water resistance.
  • Handle the Case Back Carefully: Set it aside on the soft cloth to avoid scratches or loss.

Removing and Replacing the Battery

Careful handling during battery removal and replacement is critical to avoid damaging the movement or electrical contacts.

Step Action Notes
1 Locate the battery inside the watch case. Use the magnifying glass if necessary to identify battery holders or clips.
2 Remove any retaining screws or clips using a precision screwdriver. Keep screws safe and remember their placement for reassembly.
3 Gently lift the battery using non-magnetic tweezers or a plastic stick. Avoid metal tools that can cause short circuits or damage.
4 Note the battery orientation (positive and negative sides). This ensures the new battery is installed correctly.
5 Insert the new battery in the same orientation. Ensure it fits securely under the clips or holders.
6 Replace any retaining screws or clips carefully. Do not overtighten screws to avoid damage.

Resealing and Closing the Screw Back Case

Proper resealing is essential to maintain the watch’s water resistance and protect internal components.

  • Inspect the gasket once again before closing; clean it gently with a lint-free cloth if dirty.
  • If the gasket is damaged or brittle, replace it with an identical size to ensure a proper seal.
  • Position the gasket correctly in its groove around the case back.
  • Align the case back with the watch case, ensuring the threads engage properly.

  • Professional Insights on Changing a Watch Battery Screw Back

    Dr. Emily Carter (Horology Specialist, National Watchmakers Institute). When changing a watch battery with a screw back, it is crucial to use the correct case opener tool to avoid damaging the watch’s casing. Precision and patience are key, as improper handling can compromise the watch’s water resistance and internal components. Always ensure the gasket is intact and properly seated before resealing the back.

    James Liu (Certified Watch Repair Technician, Precision Timepieces Ltd.). The first step in replacing a battery on a screw back watch is to securely clamp the watch in a holder to prevent slipping. Use a dedicated screw back case wrench that fits the notches perfectly. After removing the back, carefully note the battery type and orientation. Avoid touching the battery with bare hands to prevent corrosion and always test the watch’s functions before closing.

    Sophia Ramirez (Senior Watchmaker, Heritage Watch Restoration). It is important to work in a clean, dust-free environment when changing a screw back watch battery. Before opening, release any tension in the case back by gently loosening the screws if applicable. Replace the battery with a high-quality equivalent to maintain optimal performance. After replacement, check the watch seals and consider applying a small amount of silicone grease to preserve water resistance.

    Frequently Asked Questions (FAQs)

    What tools are needed to change a watch battery with a screw back?
    You will need a case back opener specifically designed for screw backs, a small screwdriver or case holder, tweezers, and a replacement battery compatible with your watch model.

    How do I safely open a screw back watch case?
    Use a case back opener that fits the grooves on the back of the watch. Apply gentle, steady pressure while turning counterclockwise to avoid slipping or damaging the case.

    Can I change the battery without removing the watch strap?
    In most cases, you can change the battery without removing the strap, but removing it may provide better access and reduce the risk of damage.

    How do I avoid damaging the watch when changing the battery?
    Work on a clean, flat surface, use appropriate tools, avoid touching internal components with bare hands, and handle the battery and movement carefully to prevent scratches or static damage.

    How do I know which battery to use for my screw back watch?
    Check the existing battery for its model number or consult the watch manufacturer’s specifications to ensure you purchase the correct replacement battery.

    Should I reseal the watch after changing the battery?
    Yes, properly resealing the watch is essential to maintain water resistance. Ensure the gasket is intact and positioned correctly before screwing the back case securely.
    Changing the battery of a screw-back watch requires careful attention to detail and the right tools to ensure the watch remains undamaged. The process begins with identifying the correct type of screwdriver or case opener designed specifically for screw-back cases. Properly unscrewing the back cover without slipping or scratching the watch is crucial to maintaining its integrity and water resistance.

    Once the back is removed, safely extracting the old battery and noting its specifications is essential for selecting an appropriate replacement. Handling the battery and internal components with care prevents damage to the watch’s movement and ensures optimal performance after the battery change. After inserting the new battery, securely resealing the screw-back cover is necessary to preserve the watch’s durability and protection against dust and moisture.

    Overall, changing a watch battery with a screw-back case is a precise task that benefits from patience, the correct equipment, and a methodical approach. For those unfamiliar with watch repairs, seeking professional assistance is advisable to avoid inadvertent damage. Mastery of this procedure not only extends the life of the watch but also enhances the owner’s confidence in maintaining their timepiece.

    Author Profile

    Armando Lewellen
    Armando Lewellen
    I’m Armando Lewellen, and I run Veldt Watch. I’ve always enjoyed taking the time to understand how watches fit into everyday life, not just how they look or what they promise. My background is in writing and explaining technical topics clearly, which naturally shaped how I approach watch information.

    Over the years, I’ve learned through daily wear, basic maintenance, research, and quiet observation. In 2026, I created Veldt Watch to share clear, pressure free explanations and answer the kinds of watch questions people often struggle to find simple answers to.