You can replace the battery yourself in about two minutes with a coin
The battery in your Hyundai Tucson key fob dies like any other battery—usually after three to four years of regular use. You do not need to visit a dealer or pay a technician. The fob opens with a coin, the battery slides out, and a new one slides in. The whole job takes longer to find the right battery at the store than to do the swap.
Most Tucson key fobs use a CR2032 battery, which costs between $3 and $8 at any pharmacy, grocery store, or hardware store. Some older models use a CR2025. If you are not sure which one your fob needs, you can open it first and look at the battery itself—the number is printed right on it.
Key Takeaways
- Hyundai Tucson key fobs almost always use a CR2032 battery, available at any drugstore or supermarket for under $10.
- You open the fob by inserting a coin into the slot on the edge and twisting gently until the two halves separate.
- The battery sits in a small metal holder and lifts straight out; the new one goes in the same way with the + side facing up.
- After you close the fob, test the buttons to make sure the lock, unlock, and panic functions work before you put the old battery away.
What you need to open the fob
Gather a coin—a penny, dime, or quarter all work—and the replacement battery. You do not need tools, screwdrivers, or anything else. If you do not have the replacement battery yet, open the fob first to confirm the battery type, then buy the right one.
Set yourself up at a table or counter where you have good light and a flat surface. Key fob parts are small and straightforward to drop. If you have a small dish or cup nearby, use it to hold the battery and any small parts while you work.
How to open the Tucson key fob
Look at the edge of your key fob. You will see a thin slot running along one side—this is where the coin goes. Insert the coin into the slot and twist it gently, as if you were opening a battery compartment on a toy or remote control. You are not forcing it; a light twist is enough. The two halves of the fob will separate.
Once the fob cracks open, you can pull the two halves apart with your fingers. Set the top half aside on your table. The bottom half holds the battery and the circuit board. Do not lose the rubber gasket—the thin rubber seal that sits between the two halves. You will need to put it back in the same spot.
Removing the old battery and installing the new one
The battery sits in a small metal holder with two tiny clips. You do not need to remove the holder. straightforward lift the battery straight up and out of the clips. It will come free easily—do not pry or force it.
Before you put the new battery in, look at which side is facing up. The new battery should go in with the + (plus) side facing up, just like the old one was. Slide it into the metal holder until it sits flat and the clips hold it in place. The battery should not move or rattle.
Closing the fob and testing it
Make sure the rubber gasket is still in place on the bottom half of the fob. Line up the two halves so they fit together evenly, then press them together firmly until you hear or feel a click. The fob should close completely with no gaps.
Test all the buttons right away: lock, unlock, and panic (if your fob has one). Walk to your Tucson and press the lock button from a few feet away to make sure the doors lock. Press unlock and listen for the doors to unlock. If all the buttons work, you are done. If a button does not work, open the fob again and make sure the battery is seated all the way in the holder and the + side is facing up.
What to do if the fob still does not work
If you installed a new battery and the buttons still do not respond, the problem is usually not the battery. The most common cause is that the battery was installed upside down—the + side facing down instead of up. Open the fob again and flip the battery.
If the battery is in correctly and the fob still does not work, the circuit board or buttons inside may be damaged. Water damage is another possibility if the fob has been dropped in water or exposed to moisture. In either case, you will need a replacement fob from a Hyundai dealer or an aftermarket supplier. A dealer can program a new fob to your vehicle; an aftermarket fob may require programming as well, which some dealers charge for.
Where to buy the replacement battery
CR2032 batteries are sold everywhere: pharmacies like CVS and Walgreens, grocery stores, Target, Walmart, Amazon, and hardware stores. You do not need a special automotive battery—a regular CR2032 works fine. Buy one or two extras and keep them in a drawer at home. They last for years before they expire, and you will have one ready the next time your fob dies.
Frequently Asked Questions
Can I use a different battery size if I cannot find a CR2032?
No. The CR2032 is the correct size for most Tucson fobs, and using a different size can damage the fob or cause it to malfunction. If your fob uses a CR2025 instead, that is the only battery that will work. Open the fob and check the number on the old battery to be sure.
How long does a key fob battery usually last?
Most CR2032 batteries last three to four years in a key fob, depending on how often you use the buttons. Heavy use shortens the life. If your fob starts responding slowly or you have to press buttons multiple times, the battery is dying and should be replaced soon.
What if I drop the battery or lose the rubber gasket?
If you lose the rubber gasket, the fob will still work but water can seep inside and damage the circuit board over time. You can order a replacement gasket online or from a Hyundai dealer for a few dollars. If you drop the battery and cannot find it, just buy a new one—they cost less than $10.
Do I need to reprogram the fob after changing the battery?
No. Changing the battery does not erase the programming. As long as the new battery works and the fob powers on, it will work with your Tucson right away without any reprogramming.
What if the fob is stuck and I cannot open it with a coin?
Try a different coin—sometimes a quarter gives you better grip than a penny. Make sure you are twisting in the right direction; the slot should turn like a screw. If it still will not budge, do not force it. A Hyundai dealer can open it for you, or you can order a replacement fob online and have it programmed at a dealer.