You can replace a Hyundai key fob battery yourself in minutes with no tools
Most Hyundai key fobs use a coin-cell battery — typically a CR2032 or CR2025 — that you can swap out without a trip to the dealer. The fob opens by hand or with a flathead screwdriver, the old battery slides out, and a new one slides in. The whole job takes about five minutes and costs between $3 and $8 for the replacement battery.
The exact steps depend on which Hyundai model and fob generation you own, but the principle is the same across nearly all of them. This guide covers the most common designs. If your fob looks different, check your owner's manual or search your specific model year online — Hyundai publishes the procedure for most vehicles.
Key Takeaways
- Hyundai key fobs almost always use a CR2032 or CR2025 coin-cell battery that you can buy at any pharmacy, grocery store, or hardware store for $3 to $8.
- The fob opens by sliding a small notch with your fingernail or a flathead screwdriver — no special tools or dealer visit required.
- Once open, the battery sits in a metal holder and slides out sideways; note which side faces up before you remove it so you install the new one the same way.
- If the fob still does not work after you install a new battery, the problem is likely a worn contact or a dead fob circuit, not the battery itself.
What battery your Hyundai key fob needs
The vast majority of Hyundai key fobs use a CR2032 coin-cell battery. This is a flat, round silver battery about the size of a dime. You can find CR2032 batteries at any pharmacy (CVS, Walgreens), grocery store, or hardware store in the watch and battery aisle. They cost between $3 and $8 depending on the brand.
A smaller number of Hyundai fobs use a CR2025, which is the same diameter but slightly thinner. If you are unsure which one your fob needs, open the fob and look at the battery holder — the number is printed on the metal case. Buy that exact number.
Do not buy a generic or off-brand battery if you can avoid it. Duracell, Energizer, and Panasonic coin cells last longer and hold voltage better than dollar-store versions. The price difference is small, and a better battery means your fob will work reliably for another two to three years.
How to open your Hyundai key fob
Most Hyundai fobs open by sliding a small notch or seam on the edge. Look at the sides of the fob for a thin line or slot — this is where the two halves separate. Use your fingernail to pry gently at that spot, or use a flathead screwdriver if your nail is not strong enough. Do not force it; if you are prying in the wrong spot, the fob will not budge.
Once you find the right seam, slide your nail or screwdriver along it slowly. You will feel the two halves start to separate. Continue sliding until the fob opens like a clamshell. Some fobs open all the way; others open just enough to see the battery.
If your fob has a small screw visible on the back, you will need a Phillips screwdriver to remove it before the fob opens. This is less common on newer Hyundai models but does happen. Once the screw is out, the fob should open by hand or with gentle prying.
Removing and replacing the battery
Inside the fob, you will see a round metal holder with the battery sitting in it. The battery is held in place by a metal tab or spring on one side. Look at which side of the battery faces up — this matters, because the new battery must go in the same way.
Slide the battery out sideways, away from the metal tab. Do not pry it straight up, as this can damage the holder. Once the old battery is out, take your new CR2032 (or CR2025) and slide it in the same way, with the same side facing up. The battery should sit flat and flush with the holder.
If the battery does not slide in smoothly, stop and check the orientation. Coin-cell batteries are marked with a + on one side and a – on the other. The + side should face up in most Hyundai fobs, but check the holder for any markings that tell you which way it goes. If you install it backwards, the fob will not work, but the battery will not be damaged — just flip it and try again.
Closing the fob and testing it
Once the new battery is in place, close the fob by pressing the two halves together. You should hear or feel a small click as they snap back into place. If your fob had a screw, replace it now and tighten it by hand — do not over-tighten.
Test the fob by pressing the lock and unlock buttons while standing near your Hyundai. You should see the lights flash and hear the locks respond. If the fob works, you are done. If it does not, try opening the fob again and checking that the battery is seated all the way in the holder and facing the right direction.
What to do if a new battery does not fix the fob
If you installed a fresh battery and the fob still does not work, the problem is not the battery. The most common culprit is a worn or corroded contact inside the fob. Over time, the metal contacts that touch the battery can tarnish or wear thin, breaking the electrical connection.
You can try cleaning the contacts with a pencil eraser or a small piece of fine sandpaper. Gently rub the metal contacts inside the battery holder and on the back of the battery itself, then reinstall the battery and test again. This fixes the problem in about half of cases where a new battery does not work.
If cleaning the contacts does not help, the fob circuit itself may be dead. At that point, you will need a replacement fob from a Hyundai dealer or a third-party supplier. A new fob costs between $100 and $300 depending on the model, and the dealer can program it to your vehicle in about 15 minutes.
Where to buy a replacement battery
CR2032 batteries are sold almost everywhere. Pharmacies like CVS and Walgreens stock them in the watch and battery aisle. Grocery stores like Walmart and Target carry them near the pharmacy or in the electronics section. Hardware stores like Home Depot and Lowe's have them in the electrical aisle. You can also order them online from Amazon, eBay, or any retailer that sells batteries.
Buy a name-brand battery if possible — Duracell, Energizer, or Panasonic. These cost a dollar or two more than generic versions but last significantly longer and are less likely to leak inside your fob. If you buy a pack of four or eight, you will have spares on hand for other devices like car key fobs, watches, or calculators.
Frequently Asked Questions
Can I use a different battery size if I cannot find a CR2032?
No. A CR2025 is slightly thinner and may fit loosely, causing poor contact. A CR2016 is too thin. Always use the exact battery size printed on the metal holder inside your fob. If your local store does not have it, order online — CR2032 batteries are common enough that you should receive them within a day or two.
Does it matter which side of the battery faces up?
Yes. The positive (+) side almost always faces up in Hyundai fobs, but check the metal holder for markings. If you install the battery backwards, the fob will not work, but no damage occurs — just open it again and flip the battery. If you are unsure, try it one way; if it does not work, flip it and try again.
How long does a new battery last in a Hyundai key fob?
A quality CR2032 battery typically lasts two to three years in a key fob, depending on how often you use it. If you press the buttons multiple times a day, the battery will drain faster. If you use the fob only occasionally, it may last longer.
What if my fob has a screw I cannot remove?
Use a Phillips screwdriver that fits the screw head snugly — a screwdriver that is too small will slip and strip the screw. If the screw is stuck, explore a tiny drop of penetrating oil like WD-40 and wait 10 minutes, then try again. Do not force it, as stripping the screw will make it impossible to open the fob without damaging it.
Can I replace the battery in a smart key or push-button fob the same way?
Most Hyundai smart keys and push-button fobs open the same way as traditional key fobs and use the same CR2032 battery. However, some newer models have a different design. Check your owner's manual or search your specific model year online to confirm the procedure before you start.