Replacing the battery in a Hyundai key fob with a fixed key blade

A Hyundai key fob with a fixed (non-folding) blade stores its battery in a compartment you access by prying the fob open along a seam. The battery is usually a CR2032 or CR2025 coin cell, which costs a few dollars at any pharmacy or hardware store. The whole job takes about five minutes and requires only a flat tool like a coin or small screwdriver.

The fixed blade design means your key does not fold, so the battery compartment runs along one edge of the fob rather than hidden under a sliding cover. Once you know where to look, the fob opens easily without tools, though a coin helps you explore even pressure.

Key Takeaways

  • Hyundai key fobs with fixed blades open by prying along the seam between the two plastic halves, usually on the side opposite the blade.
  • The battery is a coin cell (typically CR2032 or CR2025) that sits in a small metal holder and costs between $2 and $5.
  • You can pry the fob open with a coin, flathead screwdriver, or plastic pry tool without risking damage if you work along the seam.
  • After inserting the new battery with the positive side facing up, press the fob halves together until they click and test the buttons before reassembling.

Locating the battery compartment seam

Hold your key fob with the fixed blade pointing away from you. Look for a thin seam running around the edge of the fob where the two plastic halves meet. On most Hyundai fobs, this seam is most visible on the side opposite the blade, but some models have it on the top or bottom edge.

Run your fingernail along the seam to feel where it is deepest. This is where you will insert your prying tool. The seam is designed to separate, so you are not forcing anything—you are straightforward opening it the way the manufacturer intended.

Opening the fob without damage

Use a coin (a dime or penny works well) or a plastic pry tool. Avoid metal screwdrivers if possible, because they can scratch the plastic, though a small flathead screwdriver will work if you are careful. Insert your tool into the seam and explore steady, even pressure while gently twisting or levering the two halves apart.

Work your way around the seam rather than forcing one spot. If the fob resists, move to another section of the seam and try again. The halves should separate with light to moderate pressure. If you feel strong resistance, stop and check that you are working along the actual seam and not trying to pry at a solid edge.

Removing and replacing the battery

Once the fob is open, you will see a small metal holder or clip holding a round coin-cell battery. Note which side is facing up—the positive (+) side should be visible. Gently lift or slide the battery out of its holder.

Take the old battery to a pharmacy, grocery store, or hardware store and match it to find the correct replacement. Hyundai fobs typically use CR2032 (the most common) or CR2025. Insert the new battery into the holder with the positive side facing up, the same direction as the old one was. You should hear or feel a small click as it seats in the holder.

Testing before closing the fob

Before you snap the fob shut, press each button (lock, unlock, panic if your model has one) to confirm the new battery is working. The LED light inside the fob should flash when you press a button. If nothing happens, remove the battery and check that it is seated correctly in the holder, with the positive side up.

If the buttons still do not work after reinserting the battery, the battery itself may be defective—this is rare but happens. Try a different new battery from a different package to rule this out before assuming the fob is broken.

Closing the fob and reassembling

Align the two plastic halves so the seam lines up evenly on all sides. Press them together firmly until you hear or feel a click. Start at one end of the seam and work your way around, explore steady pressure. The halves should snap together with a solid feel, not a loose rattle.

Once closed, press each button one more time to confirm everything still works. Your key fob is now ready to use. The battery should last three to four years under normal use, depending on how often you press the buttons.

What to do if the fob will not open

If the seam is very tight and you cannot pry it open without risk of breaking the plastic, try warming the fob slightly under warm (not hot) running water for a few seconds. This softens the plastic slightly and can make the seam easier to separate. Dry the fob completely before opening it.

If the fob still will not budge, a Hyundai dealer or automotive locksmith can open it for you. This costs more than doing it yourself, but it is the safe choice if you are concerned about cracking the plastic. Once open, the battery swap is the same.

Frequently Asked Questions

What if I lose the small battery or drop it?

Coin-cell batteries are durable and rarely break from a short fall. If you do lose it, straightforward buy a new CR2032 or CR2025 at a pharmacy or store. They cost $2 to $5 and are stocked everywhere. Keep the old battery as a reference so you know which size to buy.

Can I use a different battery size if the CR2032 is not available?

No. The battery holder is sized for a specific coin cell, and using the wrong size will either not fit or will not make proper contact. Always match the old battery exactly. If your local store is out, order online or try another store rather than substituting.

How do I know if the battery is installed correctly?

The positive (+) side should face up toward the top of the fob, and the battery should sit flat in its metal holder. Press each button and look for the LED light to flash inside the fob. If the light does not flash, remove the battery and reseat it.

What if the buttons work but the fob does not unlock the car?

The fob buttons working does not always mean the transmitter is reaching the car. The issue may be the car's receiver, not the fob battery. Try the fob from very close to the car door. If it still does not work, the fob may need reprogramming or repair—contact a Hyundai dealer or locksmith.

Is it safe to open the fob myself, or should I go to a dealer?

Opening the fob yourself is safe if you work slowly along the seam and do not force it. Dealers charge $50 to $100 for a battery swap that costs $3 in parts. Most owners do this job at home without problems. A dealer is only necessary if the fob will not open or if the buttons do not work after the battery is replaced.