You can change 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, grocery store, or hardware store for a few dollars. The battery sits behind a removable cover on the back of the fob. You do not need tools or a dealer visit. The whole job takes longer to find the battery than to swap it.
The exact steps depend on which Hyundai model and fob generation you have, but the principle is the same across all of them: pry open the case, note which way the old battery sits, drop in the new one the same way, and snap the case shut. If your fob has a physical key blade inside, you may need to slide or pop that out first to access the battery compartment.
Key Takeaways
- Hyundai key fobs use CR2032 or CR2025 coin-cell batteries that cost $3 to $8 and are sold at most retailers.
- The battery compartment is on the back of the fob and opens by prying gently with a flat tool like a coin or plastic lever.
- Note the orientation of the old battery—the + side usually faces up—and install the new one the same way.
- If the fob still does not work after a fresh battery, the problem is likely the fob itself, not the battery, and you may need a replacement from a dealer.
Identify your battery type before you shop
Hyundai fobs from 2010 onward typically use either a CR2032 (the most common) or a CR2025. Both are 20 mm in diameter and look nearly identical, but the CR2025 is slightly thinner. The easiest way to know which one you need is to open your current fob and look at the battery itself—the model number is printed on the flat side.
If you cannot open the fob without breaking it, call your Hyundai dealer with your vehicle identification number (VIN) and ask which battery your fob uses. They will tell you in one call. You can also search online for your specific model year and fob generation, but the printed number on the old battery is always correct.
How to open the fob and remove the old battery
Look at the back of your fob for a seam or slot. Most Hyundai fobs have a small slot or groove on one edge where you can insert a flat tool. A coin, a plastic spoon handle, or a plastic pry tool all work—avoid metal tools that can scratch the case. Insert the tool gently into the slot and twist or lever until the back cover pops off. Do not force it; if it does not give after light pressure, you may be prying in the wrong spot.
Once the back is open, you will see the battery sitting in a shallow cup. Note which side faces up—the + (positive) side is usually on top, but check your old battery to be sure. Gently pry or pop the old battery out with your fingernail or the edge of your tool. Some fobs have a small metal clip holding the battery; if yours does, lift the clip first, then slide the battery out.
Install the new battery and close the fob
Drop the new battery into the cup with the + side facing the same direction as the old one. It should sit flat and snug. If it feels loose or tilts, you may have installed it upside down—flip it and try again. Once it is seated, close the back cover by pressing it firmly until you hear or feel a click. The cover should sit flush with the rest of the fob with no gaps.
Test the fob by pressing a button—the lock or unlock button works best. You should see the LED light up on the front of the fob, and your car should respond. If nothing happens, open the fob again and check that the battery is installed the right way and sitting all the way down in the cup.
What to do if the fob still does not work
If the LED does not light up and the car does not respond after you install a fresh battery, the problem is not the battery. The fob itself may have a broken circuit board, a cracked button contact, or water damage. At that point, a new battery will not fix it.
Your options are to buy a replacement fob from a Hyundai dealer (usually $150 to $300 depending on the model) or to look for an aftermarket fob online that matches your model year. Aftermarket fobs are cheaper but vary in quality; read reviews before you buy. If you go the dealer route, bring your VIN and ask whether the new fob will need to be programmed to your car—some models do, some do not, and the dealer can tell you before you pay.
Where to buy a replacement battery
CR2032 and CR2025 batteries are stocked at nearly every pharmacy, grocery store, and hardware store in the battery aisle. Walmart, Target, CVS, Walgreens, Home Depot, and Lowe's all carry them. You can also order them online from Amazon or eBay. Buy a name brand like Energizer, Duracell, or Panasonic rather than a no-name generic; the price difference is small and the battery will last longer and hold voltage more reliably.
Some retailers sell these batteries in multipacks of 4 or 5 for only slightly more than a single battery. If you have multiple fobs or other devices that use coin cells, a multipack is a good deal. Store unused batteries in a cool, dry place away from metal objects that could short them out.
Frequently Asked Questions
How often do I need to change my key fob battery?
Most coin-cell batteries last two to four years in a key fob, depending on how often you use it. If you press the buttons dozens of times a day, the battery will drain faster. You will notice the range getting shorter—you have to stand closer to the car for it to respond—before it dies completely.
Can I use a different battery type if I cannot find the exact one?
No. CR2032 and CR2025 look similar but are not interchangeable. A CR2025 is thinner and may not make proper contact in a fob designed for a CR2032. Always use the exact type printed on your old battery or confirmed by the dealer.
What if I lose the back cover when I open the fob?
Contact your Hyundai dealer and ask for a replacement back cover. They are inexpensive (usually under $20) and can be ordered by VIN. In the meantime, you can tape the fob shut with electrical tape to keep the battery from falling out.
Do I need to reprogram my fob after changing the battery?
No. Changing the battery does not erase the fob's programming. It will work exactly as it did before, as long as the new battery is installed correctly and the fob itself is not damaged.
Is it safe to touch the battery with my bare hands?
Yes. Coin-cell batteries are safe to handle with your hands. Wash your hands afterward if you have been handling the battery for a long time, but there is no risk from brief contact.