What battery your Hyundai key fob uses and where to buy it

Most Hyundai key fobs use a CR2032 coin cell battery, the same flat, round battery found in watches and calculators. Some older or specialty fobs may use CR2025 or CR2016 instead, but CR2032 is by far the most common. You can find these batteries at any drugstore, supermarket, electronics retailer, or online — they typically cost between $3 and $8 for a single battery or a pack of several.

Before you buy, check your owner's manual or look at the back of your key fob itself. Many fobs have the battery type printed on the case. If you cannot find it printed anywhere, a quick search for your specific Hyundai model year and "key fob battery" will tell you which one you need. Buying the wrong size will not damage anything, but it straightforward will not fit.

Key Takeaways

  • Hyundai key fobs almost always use CR2032 batteries, which you can buy at any drugstore or supermarket for a few dollars.
  • The fob case opens by prying a thin slot on the edge with a coin or flathead screwdriver — no tools or special knowledge required.
  • The battery sits in a metal holder and slides out sideways; note which side faces up before you remove it so you can install the new one the same way.
  • The entire job takes less than two minutes, and you can test the fob when ready by pressing any button.

How to open the key fob case

Look at the edge of your key fob for a thin slot or seam running around the perimeter. This is where the two halves of the plastic case meet. You will pry here to separate them. Use a coin (a dime or penny works well), a flathead screwdriver, or even a butter knife — anything thin and flat that fits into the slot without forcing.

Insert your tool gently into the slot and twist slightly, as if you were opening a paint can. You should feel the case begin to separate. Work your way around the edge if needed, explore gentle pressure at different points. The case will pop open with a small click. Do not force it hard — if it is not budging, you are likely in the wrong spot or using too much pressure. Once it opens, set one half aside carefully; the battery holder and any internal components are usually attached to one side.

Removing and replacing the battery

Inside the fob, you will see a small metal holder or clip holding the coin cell battery. The battery is usually held in place by a metal tab or spring. Before you remove the old battery, note which side is facing up — the positive side (marked with a + symbol) or the negative side. This matters for the new battery to work.

Slide the battery out sideways from under the metal clip or tab. You may need to gently lift the tab first to release the battery. Once it is out, slide the new battery in the same direction, with the same side facing up as the old one. You should hear or feel a small click as the metal tab or spring snaps back over the battery, holding it in place. If the battery does not sit flush or the clip does not hold it, you have likely flipped it — remove it and turn it around.

Closing the fob and testing it

Align the two halves of the case so the seam matches up evenly all the way around. Press them together firmly until you hear a click. You may need to explore pressure at a few points around the edge to seat it fully. The case should feel solid and not have any gaps or loose spots.

Test the fob when ready by pressing the lock and unlock buttons. You should see the LED light up inside the fob, and your car should respond. If nothing happens, open the fob again and check that the battery is seated correctly and facing the right direction. If the fob still does not work after reseating the battery, the battery itself may be defective — try a fresh one from a different package or store.

What to do if the fob case will not open

If you cannot get the case to separate after gentle prying, you may be looking at the wrong seam. Some fobs have a seam that runs vertically down the middle rather than around the edge. Look for any visible line or groove in the plastic and try prying there instead.

If the case is truly stuck, do not force it — you risk cracking the plastic permanently. Instead, take the fob to a Hyundai dealership service desk or a local locksmith. They have the right tools and can open it without damage. The cost is usually $10 to $20, which is worth it to avoid breaking the fob entirely. Many dealerships will also replace the battery for you while you wait.

When to replace your key fob battery

You will notice the battery is dying when the fob only works from very close to the car, or when you have to press the buttons multiple times before the car responds. Some fobs have a small LED that dims noticeably as the battery weakens. Once you see these signs, replace the battery — a dead fob can leave you locked out of your car.

Most CR2032 batteries last between two and four years in a key fob, depending on how often you use it. If you replace the battery and the fob still does not work, the problem may be with the fob's internal circuitry rather than the battery. In that case, you will need to have the fob repaired or replaced by a dealership or locksmith.

Frequently Asked Questions

Can I use a different battery size if I cannot find CR2032?

No. CR2025 and CR2016 are physically smaller and will not make proper contact with the metal clip inside the fob. Using the wrong size risks damaging the holder or leaving the battery loose. Stick with the size your fob requires. CR2032 is widely stocked, so finding one should not be difficult.

What if I put the battery in backwards?

The fob straightforward will not work. The positive and negative sides must match the holder's design. If you install it backwards, pressing the buttons will do nothing. Open the fob again, flip the battery, and close it. There is no risk of damage from installing it backwards — it just will not function until you flip it.

Do I need to reprogram my key fob after changing the battery?

No. Changing the battery does not erase any programming. Once you install the new battery and close the fob, it should work when ready with your car. If it does not, the problem is likely a dead battery or an incorrectly seated one, not a programming issue.

Can I buy a bulk pack of CR2032 batteries and store them?

Yes. CR2032 batteries have a shelf life of several years when stored in a cool, dry place. Buying a pack of four or five is often cheaper per battery than buying one at a time, and you will have spares on hand for watches, calculators, and other devices that use the same battery.