Watch battery changing tools are tools used to open a watch case and remove the battery, such as watchmaker's case-knives, adjustable case wrenches, tweezers and precision screwdrivers. The exact tools needed to change a watch battery vary depending on the type of case the watch has. It is possible to change some watch batteries without special tools.
A watchmaker's case-knife can pry the back off of a snap-back watch. Some snap-back watches have a notch for inserting the knife blade. Pressure on the knife handle pries the back up. If there is no notch, the knife inserts gently anywhere along the seam of the watch back.
Opening waterproof watches requires a special adjustable case wrench. Three-prong wrenches come in kits with multiple pins to open a variety of watches. The holes on the back of the watch determine which pins are inserted into the holes in the wrench. Screws on the wrench adjust to match the pins tightly to the holes in the watch. Turning the wrench screws the back off of the watch.
Tweezers and precision screwdrivers are useful for prying the old battery out of the case and setting the new battery in place. Special battery-tester tweezers have a light that tells if the battery is worn out.