Replacing a Tissot watch battery can be an easy task. The most difficult part of the job is removing the case back. Replacing a battery on an older Tissot watch requires few tools. However, newer Tissots may have pressurized case backs that require special tools and technical expertise that only a watchmaker possesses to remove. Before replacing the battery on a recently purchased Tissot, consider that the warranty will probably be voided. Only an authorized Tissot dealer can replace a battery to keep the warranty valid.
Examine the Tissot watch case back to determine whether it’s a snap-down or screw-down case back. Snap-backs are found on older models. A lip on the case back can be found at 6 or 12 o’clock. Screw-down models feature notches around the edges of the case back. If there are no notches or lip, your Tissot may have a pressurized case back. Do not attempt to remove it. Take it to a watchmaker. Skip to Step 3 if you have a notched screw-down model.
Pry open the snap-down case back with a case blade by inserting it under the lip of the case back. Push the blade down. The case back will pop off.
Insert a detached pin from the case opener into the notch of a screw-down case back to determine the correct size pins to use. Install the correct pins onto the case opener. Place the pins of the case opener into the notches. Rotate the case opener counterclockwise until the case back unscrews completely from the case. A rubber gasket will come off with the Tissot case back, according to the Watch Batteries website.
Locate the battery, which is held in place by a side-mounted spring or a flat strap over the top of the battery.
Insert a screwdriver between the spring and battery. The battery will fall out. Loosen the screw fastening the battery strap with a screwdriver if a strap is holding the battery. Do not remove the screw. Remove the battery with tweezers.
Replace the old battery. Use a clean brush to remove any dust inside the Tissot case. Insert the new battery in reverse order of the removal using the tweezers. Use the screwdriver to tighten the screw on the strap holder.
Install a new rubber gasket onto the case rim as a precautionary measure to ensure the watch remains water resistant. Make sure the gasket is seated properly against the rim.
Snap the Tissot watch case back into place with your thumb and forefinger. See Step 9 for screw-down models.
Use the case opener to screw down the case back on screw-down model. Perform this function in the reverse order of removal.