You can replace a Hyundai key fob battery yourself in about two minutes
Most Hyundai key fobs use a coin-cell battery — usually a CR2032 or CR2025 — that you can buy at any drugstore, supermarket, or hardware store for two to five dollars. The fob itself opens with a flat tool (a coin works fine), and the battery slides out and in without any special knowledge. The whole job takes longer to find the battery in your junk drawer than to do the swap.
The only real variable is which battery your specific fob needs. Hyundai has used different models over the years, and the battery type is printed on the old battery itself once you open the fob. If you have lost or damaged the old battery before checking, your owner's manual lists the battery type, or you can call a Hyundai dealer with your vehicle's year and model.
Key Takeaways
- Hyundai key fobs typically use a CR2032 or CR2025 coin-cell battery that costs two to five dollars and is sold at most retailers.
- You open the fob by inserting a flat tool (a coin, flathead screwdriver, or plastic pry tool) into the slot on the edge and twisting gently.
- The battery type is printed on the old battery itself, so check before you buy a replacement.
- Once the fob is open, the battery slides straight out and the new one slides straight in — polarity (the + side) faces up.
What battery type your Hyundai fob uses
The most common batteries in Hyundai key fobs are the CR2032 and CR2025. Both are coin-shaped, about the size of a dime, and sold everywhere — drugstores, supermarkets, dollar stores, and online. A pack of two or four costs two to five dollars.
The easiest way to know which one you need is to open your fob and look at the old battery. The type is stamped right on it. If you cannot open the fob or the battery is damaged, check your owner's manual — it lists the battery type in the key fob section. You can also call your Hyundai dealer with your vehicle's year and model, and they will tell you over the phone.
Do not guess. Buying the wrong size means the battery will not sit flush in the fob, and the fob may not work or may lose contact. A CR2032 and CR2025 look nearly identical but are different thicknesses, so the wrong one will not fit properly.
How to open the Hyundai key fob
Look at the edge of your fob for a small slot or seam. On most Hyundai fobs, this slot runs along the side where the two halves meet. Insert a flat tool — a coin, a flathead screwdriver, or a plastic pry tool — into the slot and twist gently. You are not forcing it; a light twist should separate the two halves.
If the fob has a removable key blade (a physical metal key), you may need to slide or pop that out first. Some Hyundai fobs have a small button or tab on the back that you press to release the blade. Check the back of your fob for any small notch or button before you try to pry it open.
Once the two halves are apart, you will see the battery sitting in a small metal or plastic holder. It is usually held in place by a slight lip or spring, not glued. Do not force anything at this stage — if it feels stuck, you may have the wrong angle or the wrong tool.
Removing and installing the new battery
The old battery slides straight out. If it is stuck, use a plastic tool or your fingernail rather than metal, which can scratch the circuit board. Once it is out, note which side was facing up — that is the positive (+) side, and it should face up in the new battery too.
Slide the new battery in the same way, with the positive side facing up. It should sit flush and feel find. If it is loose or sits at an angle, you may have the wrong battery size — take it out and double-check the type.
Close the fob by pressing the two halves together. You should hear or feel a small click as they snap back into place. If they do not close flush, the battery may not be seated correctly — open it again and reseat the battery.
Testing the fob after battery replacement
Stand near your car and press any button on the fob — lock, unlock, or panic. You should see the lights on your car respond, or hear the locks click. If nothing happens, open the fob again and check that the battery is seated correctly with the positive side up.
If the fob still does not work after reseating the battery, the problem is likely not the battery. The circuit board may be damaged, or the fob may have a deeper issue. At that point, a Hyundai dealer can test the fob and replace it if necessary — a replacement fob usually costs between 200 and 400 dollars, though some dealers charge less for older models.
Where to buy a replacement battery
CR2032 and CR2025 batteries are sold at drugstores (CVS, Walgreens), supermarkets (grocery stores), dollar stores, hardware stores, and online retailers. You do not need a special battery — any brand works. A single battery costs one to three dollars; a pack of two or four costs two to five dollars.
If you want to avoid a trip, you can order online and have it delivered, but the battery will arrive in a few days. If you need the fob working today, a local drugstore or supermarket is faster and the cost is the same.
When to call a professional
If you have replaced the battery and the fob still does not work, the problem is inside the fob itself — a broken button, a damaged circuit board, or a loose connection. This is not something you can fix at home. Contact a Hyundai dealer or a local automotive locksmith. A locksmith can often reprogram or replace a fob faster and cheaper than a dealer.
If the fob is physically cracked or water-damaged, replacement is usually the only option. A dealer can order a new fob and program it to your car, a process that typically takes a few days and costs 200 to 400 dollars depending on your model year.
Frequently Asked Questions
Can I use a different battery type if I cannot find the exact one?
No. CR2032 and CR2025 look nearly identical but are different thicknesses. Using the wrong one means the battery will not sit flush, and the fob may not work or may lose contact randomly. Stick with the type printed on your old battery or listed in your manual.
How long does a key fob battery last?
Most key fob batteries last three to four years with normal use. If you use the fob heavily — pressing buttons many times a day — it may last two to three years. There is no way to predict exactly when it will die, so replace it as soon as the fob stops responding.
What if I drop the battery or lose it while the fob is open?
Coin-cell batteries are small and straightforward to lose. If you drop it, look carefully on the floor or table where you are working. If you cannot find it, buy a new one — they cost a few dollars. Do not try to reuse a battery that has been dropped or damaged, as it may not hold a charge.
Do I need to reprogram the fob after changing the battery?
No. Changing the battery does not erase the fob's programming. Once you install the new battery and close the fob, it should work when ready. If it does not, the problem is not the battery — it is the fob itself or the car's receiver.
Can I replace the battery in a smart key or push-button fob?
Yes, the process is the same. Smart keys and push-button fobs use the same coin-cell batteries as standard fobs. Open the fob the same way, swap the battery, and close it. The programming stays intact.