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 or supermarket for two to five dollars. The battery sits behind a removable cover on the back of the fob. You do not need tools, a mechanic, or a dealership visit. The whole job takes longer to find the battery at the store than to swap it in your fob.
The exact steps depend slightly on which Hyundai model you own, because the fob design changed over the years. But the principle is the same: pop the cover, lift out the old battery, drop in the new one, and close the cover. This guide covers the two most common designs you will encounter.
Key Takeaways
- Hyundai key fobs use CR2032 or CR2025 coin-cell batteries that cost two to five dollars and are sold at pharmacies, supermarkets, and hardware stores.
- Most fobs have a removable back cover held by a small slot or seam that you pry open with a coin or plastic tool—no screwdriver needed.
- The battery sits in a metal holder with a plus side facing up; note which way it sits before removing it so you can insert the new one the same way.
- If your fob has a sliding battery tray instead of a removable cover, push the tray in the direction of the arrow printed on the back until it clicks free.
- Test the fob when ready after closing the cover by pressing each button to confirm the new battery works before you leave the store.
Identify which battery your fob uses
Before you buy a replacement, check what size battery your fob needs. Look at the back of your key fob for a small label or marking. Many Hyundai fobs print the battery type directly on the back cover—you may see "CR2032" or "CR2025" stamped or printed there. If you do not see a label, check your owner's manual in the glove compartment or search online for your specific model year and fob design.
CR2032 is the most common size in Hyundai fobs made in the last ten years. CR2025 is slightly thinner but works in some older models. If you are unsure, buy a CR2032—it is the standard coin-cell battery and will fit most fobs. If it does not fit, you can return it and swap for a CR2025.
Open the fob with a removable back cover
Most newer Hyundai fobs have a back cover that slides or pops off. Look at the seam where the back cover meets the rest of the fob. You will usually see a small slot or groove running along one edge. Insert a coin—a dime or penny works well—into that slot and twist gently, as if you were opening a battery compartment on a remote control. The cover will pop free.
If you do not see a slot, look for a small arrow or line printed on the back. Some fobs have a sliding tray instead: push the tray in the direction the arrow points until you hear a click and the tray slides out. Do not force it. If it does not move easily, you may be pushing the wrong direction—flip the fob and try the other way.
Once the cover is off or the tray is out, you will see the battery sitting in a metal holder. The battery is round and flat, about the size of a dime. Note which side is facing up—the plus sign should be visible on top. This matters when you put the new battery in.
Remove the old battery and insert the new one
Gently lift the old battery out of the metal holder. It should come free with light pressure from your fingernail or a plastic tool. Do not use a metal screwdriver or anything sharp, because you can damage the holder or the circuit board underneath.
Before you insert the new battery, check that the plus sign is facing up, just as it was on the old battery. Slide the new battery into the metal holder with the plus side up. It should sit flat and flush with the holder. If it does not sit flat, flip it over—you may have inserted it upside down.
Close the back cover or slide the tray back into place until you hear a click. The cover should sit flush with the rest of the fob with no gaps. If the cover does not close all the way, the battery may be inserted upside down or sitting crooked—pop the cover back off and reseat the battery.
Test the fob before you leave
Press each button on the fob—lock, unlock, panic, trunk, or whatever buttons your model has. You should see the LED light on the front of the fob blink when you press a button. If the light blinks, the battery is working and you are done.
If the light does not blink or blinks very faintly, the battery may be inserted upside down or the cover may not be closing all the way. Pop the cover off again, check that the plus sign is facing up, and reseat the battery. Close the cover firmly and test again.
If you are still at the store, test the fob right there before you leave. If the fob does not work after you get home, you can return to the store and swap the battery for a different size or brand. Most stores will let you exchange a battery if it does not work in your device.
What to do if the fob still does not work
If you installed a new battery and the fob still does not respond, the problem is usually not the battery. The most common cause is that the battery was inserted upside down or the cover is not closing all the way. Open the fob one more time and check both of these things.
If the battery is in correctly and the cover closes flush, the fob may have a dead circuit board or a broken button. This is rare but does happen, especially in older fobs. In that case, you will need a replacement fob from a Hyundai dealership. Bring your car keys and proof of ownership, and the dealership can order a new fob and program it to your car. This usually costs between 100 and 300 dollars depending on your model year.
Before you assume the fob is broken, also try replacing the battery one more time with a fresh battery from a different package or brand. Occasionally a battery is defective right out of the box, and swapping it for another one solves the problem.
Frequently Asked Questions
Where can I buy a CR2032 battery?
CR2032 batteries are sold at pharmacies (CVS, Walgreens), supermarkets (grocery stores), hardware stores (Home Depot, Lowe's), and online retailers (Amazon). They usually cost between two and five dollars. Buy a name brand like Energizer or Duracell if you can—they last longer than generic batteries and rarely fail.
Can I use a different size battery if I cannot find a CR2032?
CR2025 will work in some Hyundai fobs, but it is thinner and may not make proper contact with the metal holder. CR2016 is too small. Stick with CR2032 or CR2025 only, and check your fob label or owner's manual to be sure. If your store is out of the right size, order online or try another store.
How often do I need to replace the battery?
A CR2032 battery in a key fob usually lasts two to four years, depending on how often you use the fob. If you use your fob multiple times a day, the battery may last closer to two years. If you use it rarely, it may last four years or longer. You will notice the fob responding more slowly or the LED blinking dimly before the battery dies completely.
What if I drop the battery and cannot find it?
Coin-cell batteries are small and straightforward to lose. If you drop it, look on the floor and under nearby furniture. If you cannot find it, just buy a new one—they are cheap. Do not try to reuse a battery that has been dropped or exposed to water, because it may be damaged inside even if it looks fine.
Do I need to reprogram my fob after changing the battery?
No. Changing the battery does not erase the fob's programming. Once you close the cover and the new battery makes contact, the fob will work exactly as it did before. You do not need to visit a dealership or do anything else.