You can replace a Timex Ironman battery yourself with a small screwdriver and a replacement battery, or take it to a jeweler or watch repair shop
Timex Ironman watches use a standard coin-cell battery—usually a CR2032, CR2016, or SR626SW depending on your model—that you can buy at any drugstore, supermarket, or online retailer for $3 to $8. The watch back is held on by a small screw or is a snap-fit case. If you are comfortable with small tools and do not mind the risk of scratching the case, you can do this yourself in about five minutes. If you would rather not open the watch, a jeweler or watch repair shop will do it for $10 to $25, often while you wait.
The whole job comes down to three steps: opening the back, swapping the battery, and closing it again. The hardest part is usually just getting the back off without scratching it. Once you have done it once, the second time takes even less time.
Key Takeaways
- Timex Ironman watches use a CR2032, CR2016, or SR626SW battery; check your manual or the old battery to know which one to buy.
- The watch back either unscrews with a small Phillips or flathead screwdriver, or pops off by hand or with a plastic tool.
- Once the back is open, note the battery orientation (+ side up or down), remove the old battery, and slide the new one in the same way.
- If the watch back is sealed or you are uncomfortable opening it, a jeweler can replace the battery for $10 to $25.
- After installation, test all functions—time, stopwatch, alarms, backlight—to confirm the battery is making good contact.
Find out what battery your Ironman model uses
The easiest way is to look at the old battery itself. Open the watch back (see the next section), remove the battery, and read the code printed on it. That code—CR2032, CR2016, SR626SW, or another—is what you need to buy.
If you cannot open the watch or the battery is too worn to read, check your Timex Ironman manual. The manual lists the battery type by model number. You can also search online for "[your model number] battery type"—for example, "Timex Ironman T5K494 battery"—and the answer usually appears in the first few results or in user forums.
Unscrew or pop off the watch back
Most Timex Ironman watches have one of two types of case back: a screw-on back or a snap-fit back. Look at the back of your watch. If you see a small slot or groove running around the edge, it is a screw-on back. If the back looks smooth with no visible seam, it is likely a snap-fit.
For a screw-on back: Use a small Phillips or flathead screwdriver—a jeweler's screwdriver set works best because the blades are thin and fit snugly. Place the screwdriver in the slot and turn counterclockwise slowly. Do not force it; if it does not turn easily, you may have the wrong screwdriver size. Once loose, unscrew by hand and set the screw somewhere safe. Lift the back straight up and away from the watch.
For a snap-fit back: Try to pry it open gently with your fingernail or a plastic spoon handle along the edge. If that does not work, a plastic watch-opening tool (available online for $5 to $10) or a guitar pick can slide into the seam without scratching the case. Work your way around the edge, lifting gently, until the back pops free.
Remove the old battery and note its position
Once the back is open, you will see the battery sitting in a small metal holder or clip. Before you touch it, look at which side is facing up. The battery has a + symbol on one side and is blank or marked − on the other. Write down or remember which side faces up—this matters for the new battery to work.
Gently pry the battery out with a plastic tool, your fingernail, or the edge of a plastic spoon. Do not use a metal tool, as it can scratch the battery or the watch interior. Once the old battery is out, set it aside. If the metal contacts inside the watch look dirty or corroded (dark or crusty), wipe them gently with a dry cloth or a cotton swab.
Install the new battery in the same orientation
Take your new battery and slide it into the holder with the + side facing the same direction as the old battery was facing. The battery should sit flat and click or snap into place. Do not force it; if it does not sit easily, you may have the wrong battery type or the orientation is backwards.
Once the new battery is in, gently press down on it to make sure it is making contact with the metal clips. You should feel a slight resistance. Do not press so hard that you bend the clips.
Close the watch back and test all functions
If your watch has a screw-on back, align the back with the case and screw it in by hand first, then tighten gently with your screwdriver. Do not over-tighten, as this can strip the screw or crack the case. If your watch has a snap-fit back, press it down firmly around the edges until you hear or feel it click into place all the way around.
Now test the watch. Press the buttons to confirm the time display works, the stopwatch starts and stops, any alarms sound, and the backlight turns on. If nothing happens, the battery may not be making contact. Open the back again, remove the battery, and reinstall it, making sure it sits flat and the + side is facing the correct direction.
When to take your watch to a professional
If the watch back is sealed or glued shut, or if you do not feel comfortable opening it, a jeweler or watch repair shop is the right choice. Many jewelry stores and some pharmacies with watch departments will replace the battery while you wait for $10 to $25. Some big-box retailers with jewelry counters also offer this service. Call ahead to confirm they work on Timex watches and ask about the cost and turnaround time.
You should also take your watch to a professional if it stops working after you install a new battery, or if water gets inside the case during the replacement. A jeweler can test the watch, replace the battery correctly, and reseal the case if needed.
Frequently Asked Questions
What if I put the battery in backwards?
The watch will not work. The battery will not make electrical contact if the + and − sides are reversed. Open the back, flip the battery around so the + side faces the correct direction, and close it again. The watch should turn on when ready.
Can I use a different battery type than the one listed?
No. Different battery types have different voltages and sizes. Using the wrong battery can damage the watch circuit or not fit in the holder at all. Always use the exact type listed in your manual or printed on the old battery.
How long does a new battery last in a Timex Ironman?
Most CR2032 and CR2016 batteries last 2 to 5 years in a Timex Ironman, depending on how often you use the backlight and stopwatch. SR626SW batteries typically last 1 to 2 years. Heavy use of the backlight shortens battery life.
Is it safe to open my watch if it is water-resistant?
Opening the watch breaks the water-resistant seal. After you close it again, the watch is no longer water-resistant unless you take it to a jeweler who can reseal it properly. If your watch is rated for water resistance and you plan to wear it in water, have a professional replace the battery instead.
What should I do with the old battery?
Do not throw it in the trash. Take it to a battery recycling program, a Best Buy or other electronics retailer that accepts batteries, or a hazardous waste collection event in your area. Many drugstores and supermarkets also have battery drop-off bins near the customer service desk.