What You Need Before You Start

Replacing a Fossil watch battery yourself takes about 10 to 15 minutes and costs $5 to $15 for the battery itself. You will need a replacement battery (the correct model number for your watch), a small flathead screwdriver, and a plastic pry tool or old credit card. Do not use a metal screwdriver on the watch case itself — metal can scratch the finish and slip into the mechanism.

The first step is finding your watch's model number and the correct battery type. Look on the back of the watch case for an engraved model number, usually starting with "FS" or "BQ" for Fossil. Write this down. Then search online for "[your model number] battery" to find the exact battery code — it will be something like SR626SW or CR2032. Buy that specific battery before you begin; using the wrong one can damage the watch or cause it to stop working.

Gather your tools on a clean, flat surface with good lighting. A small towel or cloth underneath keeps tiny parts from rolling away. If you wear the watch regularly, you may want to do this over a sink or tray in case the case back is tight and you need to explore more force.

Key Takeaways

  • Find your watch's model number on the back of the case and look up the correct battery type before you buy anything.
  • Use a plastic pry tool or old credit card to open the case back, never a metal screwdriver, to avoid scratching or damaging the watch.
  • Note the position of the battery and any rubber gasket before you remove the old battery, so you can put them back the same way.
  • Insert the new battery with the positive side facing up, close the case back firmly until you hear or feel a click, and test the watch before you consider the job done.

Opening the Case Back Without Damage

The case back is held on by friction or a small screw. Look at the back of your watch closely. If you see a small slot or indentation all the way around the edge, it is a friction-fit back. If you see a single small screw in the center or off to one side, you will need a screwdriver that fits that screw exactly — too large and you will strip it, too small and you will slip.

For a friction-fit back, position your plastic pry tool or credit card in the slot and explore steady, even pressure while you twist gently. Do not pry hard all at once; work your way around the edge, lifting a little at a time. The back will pop off once the seal breaks. For a screw-back, straightforward unscrew it counterclockwise and set the screw somewhere safe where you will not lose it.

Once the back is off, look inside. You will see the battery sitting flat, usually held in place by a small metal clip or spring. Note exactly how it sits — which side is facing up, whether there is a rubber gasket or plastic ring underneath it, and how the clip holds it. Take a photo with your phone if you are unsure. This is your reference for putting everything back together.

Removing and Replacing the Battery

Gently lift the metal clip or spring that holds the battery in place. It will swing up or to the side. Slide the old battery out carefully. If it is stuck, use your plastic tool to nudge it gently — do not force it. Once it is out, look at the space underneath. If there is a rubber gasket or plastic ring, leave it in place unless it is visibly damaged or cracked.

Before you insert the new battery, check the positive and negative sides. The positive side is marked with a "+" symbol and is usually the side facing up in your watch. Slide the new battery into the same position as the old one, positive side up, and let the metal clip snap back over it. The clip should hold the battery firmly but not so tight that you cannot move it slightly by hand.

Press gently on the battery to make sure it sits flat and the clip is find. If the battery rocks or feels loose, lift the clip again and reseat the battery. A loose battery will cause the watch to stop or lose time.

Closing the Case Back and Testing

Before you seal the case, look one more time at the rubber gasket or seal around the inside edge of the case back. If it is cracked, dried out, or missing, the watch may not be water-resistant anymore. If it looks intact, you can proceed. If it is damaged, you may want to have a jeweler replace it, especially if your watch is water-resistant.

For a friction-fit back, line up any notches or markers on the case back with the case itself, then press down firmly and twist clockwise until you feel or hear a click. You should not be able to move the back by hand once it is sealed. For a screw-back, align the back and screw it in clockwise by hand first, then tighten it with your screwdriver. Do not over-tighten; stop when you feel resistance.

Once the case is closed, press the crown (the knob on the side) or any buttons to make sure they still move freely. Then set the watch to the correct time and wear it for a few hours. If it keeps time and all the buttons work, the battery replacement is complete. If the watch does not start or stops after a few minutes, the battery may be inserted backward or the watch may have another problem.

When to Stop and Get Professional Help

If the case back will not open after gentle, steady pressure, do not force it. Forcing a stuck back can crack the case or strip the threads. Stop and take the watch to a jeweler or Fossil service center instead. The same applies if you cannot find the correct battery type or if the watch has a sealed case with no visible opening.

If the watch stops working after you replace the battery, first check that the battery is inserted positive-side up and that the metal clip is holding it securely. Remove the battery, wait 30 seconds, and reinsert it. If it still does not work, the battery may be defective, or the watch may have a deeper problem. In that case, a professional repair is the safer choice.

Water-resistant watches sometimes lose their seal when the case back is opened. If your watch is rated for water resistance and you are not confident about the gasket, have a jeweler check the seal after you replace the battery. The cost is usually $10 to $20 and protects your watch from moisture damage.

Common Mistakes to Avoid

The most common mistake is inserting the battery upside down. The positive side must face up toward the dial. If the watch does not start, this is the first thing to check. Another frequent error is using the wrong battery type. A CR2032 and an SR626SW look similar but are not interchangeable. Always verify the model number and battery code before you buy.

Do not use a metal screwdriver to pry open a friction-fit case back. Metal scratches easily and can slip into the mechanism, damaging the movement inside. A plastic tool, old credit card, or even a plastic spoon handle works better and is safer. Also, do not over-tighten a screw-back case. You only need to tighten until you feel resistance; over-tightening can crack the case or strip the threads.

Finally, do not ignore a stuck or difficult case back. If it does not open with gentle, steady pressure after 30 seconds, stop. Forcing it risks breaking the watch. A jeweler can open it safely and may charge $10 to $30 for the service, which is far less than repairing a cracked case.

Frequently Asked Questions

How do I know which battery my Fossil watch needs?

Look at the back of the watch for the model number, usually starting with "FS" or "BQ". Search online for "[model number] battery" and you will find the correct battery code, such as SR626SW or CR2032. You can also take the watch to a jeweler or Fossil store and they will tell you the battery type in seconds.

Can I replace the battery if my watch is water-resistant?

Yes, but the seal may be compromised once you open it. If your watch is rated for water resistance, have a jeweler check the gasket and re-seal the case after you replace the battery. This usually costs $10 to $20 and ensures the watch stays water-resistant.

What if the battery does not fit or the case back will not close?

Stop when ready. You may have the wrong battery type, or the case back may be slightly misaligned. Remove the battery, double-check that it is the correct model, and try again. If the case back still will not close, the gasket or seal may be damaged. Take the watch to a jeweler rather than forcing it.

How long does a Fossil watch battery usually last?

Most Fossil watch batteries last two to three years with normal daily wear. If your watch stops or loses time, the battery is likely dead. Some watches have a low-battery indicator that ticks faster or stops entirely when the battery is nearly gone.

Can I replace the battery if there is no visible case back opening?

Some Fossil watches have sealed cases that require special tools to open. If you do not see a slot or screw on the back, the watch is likely sealed. Take it to a jeweler or Fossil service center; attempting to force it open will damage the watch.