You can replace a Hyundai key fob battery yourself in under five minutes
Most Hyundai key fobs use a coin-cell battery — typically a CR2032 or CR2025 — that you can swap out without tools or a trip to the dealer. The fob splits open along a seam, the old battery slides out, and a new one slides in. You'll find the battery type printed on the fob itself or in your owner's manual, and replacement batteries cost between $3 and $8 at any pharmacy, grocery store, or hardware store.
The entire process takes longer to read about than to do. If your key fob is still under warranty or you're uncomfortable opening it, a Hyundai dealer can do it for you — usually for $10 to $20 plus labor — but most owners find it simpler to handle at home.
Key Takeaways
- Hyundai key fobs use replaceable coin-cell batteries, most commonly CR2032 or CR2025, which you can buy at any drugstore or supermarket.
- The fob opens by sliding a flat tool along the seam between the two halves; no screws or special equipment needed.
- The battery sits in a small metal holder and slides out horizontally; note which side faces up before you remove it.
- A new battery costs $3 to $8 and takes about two minutes to install once you have the fob open.
Locate the battery type before you buy a replacement
Check the back or side of your key fob for a printed label showing the battery model number. Most Hyundai fobs use CR2032 (the most common size) or CR2025 (slightly thinner). If you don't see a label on the fob itself, open your owner's manual and search the index for "key fob battery" or "remote battery" — the manual will list the exact type.
Once you know the model, buy a replacement at a pharmacy, grocery store, supermarket, or hardware store. You'll find them in the battery aisle, usually near the checkout counter. Buy one extra if you can; having a spare on hand means you won't need to make another trip if the first battery doesn't solve the problem or if your fob dies again in a few years.
Open the fob by sliding the halves apart
Look for a small seam running around the edge of your key fob where the two plastic halves meet. This seam is usually on the side or back of the fob, not the front. Insert a flat tool — a coin, a flathead screwdriver, a butter knife, or even a fingernail — into the seam and gently twist or slide it sideways to pry the halves apart.
Work slowly and test the seam in a few spots before you force it. The fob is designed to open this way, so it should separate with light pressure. If you meet hard resistance, you may be working on the wrong seam or pushing in the wrong direction. Once the halves start to separate, you can usually pull them apart by hand without the tool.
Remove the old battery and note its position
Inside the fob you'll see a small metal holder or clip with the battery sitting in it. The battery is round and flat, about the size of a dime. Before you remove it, note which side is facing up — the positive side (marked with a + symbol) or the negative side (marked with a − symbol). This matters because the battery will only work if it's installed the correct way.
Slide the old battery out of its holder horizontally. If it's stuck, use your fingernail or a plastic tool to gently pry it out. Do not use a metal tool that could scratch the circuit board inside the fob. Once the old battery is out, set it aside — you can recycle it at most pharmacies or electronics stores.
Insert the new battery with the correct side facing up
Take your new battery and check that it matches the model number you looked up earlier. Slide it into the metal holder with the same side facing up as the old battery was. If the old battery had the + symbol facing up, the new one should too. The battery should slide in smoothly and sit flat in the holder.
If the battery doesn't slide in easily, stop and check the orientation. Forcing it in the wrong direction can damage the holder or the circuit board. Once the battery is seated, gently press down on it to make sure it's making contact with the metal clips on both sides of the holder.
Close the fob and test the buttons
Align the two halves of the fob so the seam lines up evenly all the way around. Press them together firmly until you hear or feel a small click. The fob should close completely with no gaps. If it doesn't close all the way, the battery may not be seated correctly — open it again and check that the battery is sitting flat in its holder.
Once the fob is closed, test each button: lock, unlock, and panic (if your fob has one). Point the fob at your Hyundai from a few feet away and press each button while watching your car. The lights should flash and the doors should lock and unlock. If nothing happens, open the fob again and check that the battery is installed correctly and making good contact with the metal clips.
What to do if the new battery doesn't work
If you installed a new battery and the fob still doesn't work, the problem is usually one of three things: the battery is installed upside down, the battery isn't making contact with the metal clips, or the fob itself is damaged. Open the fob again, remove the battery, and reinstall it, paying close attention to which side faces up. Make sure the battery sits completely flat and the metal clips on both sides are touching it.
If the fob still doesn't work after you've checked the battery twice, the circuit board inside may be damaged or the fob may need to be reprogrammed to your car. Contact a Hyundai dealer with your vehicle identification number (VIN) and fob model. They can test the fob, reprogram it if needed, or replace it under warranty if it's still covered.
Frequently Asked Questions
Where can I buy a CR2032 or CR2025 battery?
Any pharmacy, supermarket, grocery store, or hardware store carries these batteries in the battery aisle. They cost $3 to $8 per battery. You can also order them online from retailers like Amazon, but buying locally means you don't have to wait for shipping.
Can I use a different battery size if I can't find the exact model?
No. The battery holder inside your fob is sized for a specific model, and using the wrong size will either not fit or won't make proper contact. Always use the exact model printed on your fob or listed in your owner's manual.
How often do I need to replace the battery?
Most key fob batteries last three to four years with normal use. You'll know it's time when the buttons stop responding or only work from very close to your car. Some fobs may last longer or shorter depending on how often you use them.
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 additional steps.
What if I accidentally drop the battery or lose it inside the fob?
If you drop the battery, it's usually straightforward to find — it's round and shiny and will be sitting somewhere inside the fob. If you lose it, buy a new one and install it. If you drop it outside the fob, wash your hands afterward; coin-cell batteries contain chemicals that can irritate skin with prolonged contact.