You can replace a Hyundai key fob battery yourself in about five minutes
Most Hyundai key fobs use a coin-cell battery — typically a CR2032 or CR2025 — that you can buy at any drugstore, grocery store, or hardware store for a few dollars. The fob itself opens with a small flathead screwdriver or a coin, and the battery slides out and in without tools. You do not need to visit a dealer or a locksmith for this task.
The exact battery type depends on your Hyundai model and year. Before you start, check your owner's manual or look up your specific model online to confirm which battery your fob needs. Once you have the right battery and a flathead screwdriver, the whole job takes less time than it takes to drive to a store.
Key Takeaways
- Hyundai key fobs typically use CR2032 or CR2025 coin-cell batteries, which cost $3 to $8 and are sold at most retailers.
- You open the fob by inserting a flathead screwdriver or coin into the slot on the side and gently twisting to separate the two halves.
- The battery sits in a small metal holder and slides out horizontally — note which side faces up before you remove it.
- After inserting the new battery with the correct side facing up, snap the fob halves back together and test all buttons before putting it away.
Finding the right battery for your Hyundai model
The battery type varies by model year and fob design. Most recent Hyundai fobs use a CR2032, but some older models or certain trim levels may use a CR2025 or CR2016. Your owner's manual lists the correct battery in the key fob section, usually near the back of the book.
If you do not have your manual, search online for "[your Hyundai model] [year] key fob battery" — owner forums and parts websites will confirm the type. You can also call a Hyundai dealer parts department and give them your vehicle identification number (VIN); they will tell you the exact battery without charging you.
Once you know the type, buy the battery at a pharmacy, supermarket, or hardware store. These batteries are inexpensive and widely stocked. Some stores keep them behind the counter, so ask if you do not see them on the shelf.
Opening the key fob safely
Look at the edge of your key fob for a small slot or seam running along one side. This is where the two halves of the fob meet. Insert a flathead screwdriver into the slot — a coin also works if you do not have a screwdriver handy.
Turn the screwdriver gently, as if you were opening a battery compartment on a toy or remote control. You are not trying to pry hard; the fob is designed to open with light pressure. The two halves will separate after a quarter turn or less. If it does not budge after gentle twisting, try the slot on a different edge — some fobs have multiple seams.
Once the halves separate, set them on a clean surface with the battery holder facing up. The battery holder is a small metal clip or tray in the center of one half.
Removing and replacing the battery
The battery sits in a metal holder and is held in place by a small clip or spring. Look at which side of the battery faces up — this matters, because the battery only works one way. The side marked with a + or a number is the positive side and should face up in most Hyundai fobs.
Gently push the battery to one side or lift the edge of the metal clip to free the battery. It will slide out easily. Do not force it. Once the old battery is out, slide the new battery into the holder with the positive side facing the same direction as the old one was facing.
If you are unsure which side should face up, check your manual or take a photo of the old battery before you remove it. You can also look inside the battery holder — there is usually a small + symbol printed on the plastic to show which side of the battery should face that direction.
Closing the fob and testing the buttons
Align the two halves of the fob so the edges match up evenly. Press them together firmly until you hear or feel a click. The fob should close flush with no gaps between the halves. If there is a gap, the halves are not seated correctly — open it again and realign them.
Once the fob is closed, test each button: lock, unlock, panic, and trunk (if your model has one). All buttons should respond when ready. If a button does not work, open the fob again and check that the battery is seated correctly in the holder and facing the right direction.
If the buttons still do not work after you have reseated the battery, the battery itself may be defective. Try a fresh battery from a different package or store. If the fob still does not work, the problem may be inside the fob itself, and you would need to contact a dealer or locksmith.
What to do if the fob still does not work
A new battery solves the problem in most cases. If it does not, the issue is usually one of three things: the battery is installed upside down, the battery is defective, or the fob has an internal electrical problem.
Start by opening the fob again and checking the battery direction. Look for the + symbol inside the holder and make sure the positive side of the battery faces that direction. Close the fob and test again.
If that does not work, try a battery from a different package or brand. Occasionally a battery is defective right out of the box. If a second battery does not work, the fob itself may have failed — this is rare, but it happens. At that point, contact a Hyundai dealer or a locksmith who works with car keys. They can test the fob and replace it if needed.
Keeping your key fob in good condition
Most key fob batteries last two to four years depending on how often you use the fob. If you notice the buttons becoming sluggish or requiring multiple presses before they work, the battery is running low — that is the time to replace it, before the fob stops working entirely.
Avoid exposing your fob to extreme heat, cold, or moisture. Do not drop it or sit on it. These things can damage the internal circuitry or the battery holder, making the fob unrepairable. If your fob gets wet, let it dry completely before using it, and consider opening it to check that the battery holder is dry inside.
Frequently Asked Questions
Can I use a different battery type if I cannot find the exact one?
No. Using the wrong battery type can damage the fob or cause it to malfunction. Stick with the type listed in your manual. If your local stores do not have it in stock, order it online — it will arrive within a day or two, and the cost is minimal.
What do I do with the old battery?
Coin-cell batteries contain small amounts of lithium or mercury and should not go in the trash. Most pharmacies and electronics stores have battery recycling bins near the checkout. Drop the old battery there, or check Earth911.com to find a recycling location near you.
Will replacing the battery erase my fob's programming?
No. The battery powers the fob but does not store the programming. Changing the battery will not affect how the fob communicates with your car. Your fob will work exactly as it did before, as soon as you close it back up.
How do I know if my fob battery is dead or if the fob itself is broken?
Replace the battery first — that solves the problem nine times out of ten. If the buttons still do not work after you have installed a fresh battery and checked that it is facing the right direction, the fob itself may be damaged. At that point, a dealer or locksmith can test it and tell you whether it can be repaired or needs to be replaced.