You can replace a Hyundai key fob battery yourself in under five minutes with a coin and the right battery type
Most Hyundai key fobs use a CR2032 or CR2025 coin-cell battery that you can buy at any drugstore, grocery store, or hardware retailer for two to five dollars. The fob itself is designed to open without tools — you just need a coin or flat object to pry the two halves apart, swap the old battery for the new one, and snap it back together. The whole job takes longer to find your coin than to do the work.
The hardest part is knowing which battery your specific fob needs. Hyundai has made dozens of fob designs over the years, and not all of them use the same battery. Before you buy anything, you need to open your fob and look at what is inside, or check your owner's manual or Hyundai's website for your model year.
Key Takeaways
- Hyundai key fobs typically use CR2032 or CR2025 batteries, which cost two to five dollars and are sold everywhere.
- You open the fob by inserting a coin into the slot on the edge and twisting gently until the two halves separate.
- The battery slides or clips into a holder inside the fob — note which side faces up before you remove it.
- After inserting the new battery, press the fob halves together firmly until you hear or feel a click, then test all the buttons.
- If the fob still does not work after a new battery, the problem is likely the fob itself, not the battery.
Find out what battery your Hyundai fob uses
The easiest way is to open the fob first and look inside. Insert a coin (a dime or penny works) into the slot on the edge of the fob where the two halves meet. Twist gently — do not force it — until you feel the halves start to separate. Once there is a small gap, you can usually pry the rest open by hand.
Inside, you will see a small round battery sitting in a plastic holder. The battery itself is stamped with a code like CR2032 or CR2025. Write down that code before you close the fob again. If you do not want to open it yet, you can also check your Hyundai owner's manual or search online for your model year and fob style — Hyundai's website lists the battery type for each fob design.
Buy the correct replacement battery
Once you know the code, buy that exact battery. CR2032 and CR2025 are the most common, but some older or newer Hyundai fobs may use CR2016 or other types. Do not guess — the wrong battery will not fit or will not power the fob properly.
You can find these batteries at any pharmacy, supermarket, dollar store, or hardware store in the watch and battery section. They are also sold online through Amazon, eBay, and other retailers. A single battery usually costs between two and five dollars. Some stores sell multipacks if you want spares for other devices.
Remove the old battery and insert the new one
Open the fob the same way you did before — insert a coin into the edge slot and twist gently until the halves separate. Set the top half aside on a clean surface where you will not lose the small spring or contact inside.
Look at how the old battery sits in the holder. Note which side faces up — the side with the + symbol should face toward you (or toward the top of the fob, depending on the design). Some batteries slide out, others clip in. If it clips, gently pry one edge up with your fingernail or the coin until it pops free. If it slides, just pull it straight out.
Insert the new battery the same way the old one came out, with the + side facing the same direction. Push it down firmly until it sits flat in the holder. If it clips, you should hear or feel a small click when it locks into place.
Close the fob and test it
Press the two halves of the fob together firmly. You should hear or feel a click when they snap back into alignment. If they do not close smoothly, open it again and check that the battery is sitting flat and the spring or contact inside has not shifted out of place.
Once the fob is closed, test all the buttons — lock, unlock, trunk, panic, or whatever buttons your fob has. Walk to your car and press each button to confirm the car responds. If the fob works, you are done. If it does not, open the fob again and double-check that the battery is inserted the right way and making good contact with the metal terminals inside.
What to do if the new battery does not work
If you installed a new battery correctly and the fob still does not work, the problem is not the battery. The issue is usually a broken button contact, a cracked circuit board, or corrosion inside the fob that prevents the battery from making electrical contact.
In that case, you have two options: buy a replacement fob from a Hyundai dealer (usually 150 to 300 dollars, depending on the model) or buy an aftermarket fob online (usually 30 to 80 dollars). Aftermarket fobs work with most Hyundai models but may need to be programmed by a dealer or a locksmith. A dealer can program a new fob in about 15 minutes for a fee of 50 to 150 dollars, depending on the location and model year.
How to avoid battery problems in the future
Hyundai key fob batteries typically last three to four years with normal use. You can extend that lifespan by keeping the fob away from extreme heat, moisture, and direct sunlight. Do not leave it in a hot car, drop it in water, or expose it to humidity for long periods.
If you notice the fob is not working as well as it used to — buttons require harder presses, or the car does not respond from as far away — that is usually a sign the battery is running low. Replace it before it dies completely, so you do not get stuck unable to unlock your car.
Frequently Asked Questions
Can I use a different battery if I cannot find the exact one?
No. CR2032, CR2025, and CR2016 are not interchangeable. Using the wrong size will either not fit or will not power the fob correctly. Spend the extra minute to find the right battery — it costs the same and takes the same time to install.
Do I need to reprogram my key fob after changing the battery?
No. Replacing the battery does not erase the fob's programming. Once you install the new battery and close the fob, it should work when ready without any reprogramming.
What if the fob halves will not come apart?
Do not force it. You may have the coin in the wrong spot — look for a small slot or seam on the edge of the fob. If you still cannot find it, check your owner's manual for the exact location. Some older Hyundai fobs have the slot in a different place than newer ones.
Can I buy a generic battery instead of a name brand?
Yes. Generic CR2032 and CR2025 batteries work just as well as branded ones like Energizer or Duracell. The chemistry is the same. Buy whichever is cheaper and in stock.
How do I know if my fob battery is dead or if the fob is broken?
Replace the battery first. If the fob works after that, the battery was the problem. If it still does not work, the fob itself is damaged and needs to be replaced or repaired.