You can replace a Hyundai key fob battery yourself in about five minutes with a coin and a fresh battery

Most Hyundai key fobs use a coin-cell battery—typically a CR2032 or CR2025—that you can buy at any drugstore, supermarket, or hardware store for a few dollars. The fob itself is designed to open without tools; you just need a flat coin to pry the two halves apart, swap the old battery for the new one, and snap it back together. The whole job takes longer to find the right battery than to do it.

The exact battery type depends on your Hyundai model year and which fob you have. If you're not sure which one you need, you can check your owner's manual, look at the battery compartment itself once you open the fob, or ask the person at the store to match it when you show them the old one.

Key Takeaways

  • Hyundai key fobs use a coin-cell battery (usually CR2032 or CR2025) that costs a few dollars and is sold at most stores.
  • You open the fob by inserting a flat coin into the seam between the two halves and gently twisting to separate them.
  • The battery sits in a small metal holder; note which side faces up before you remove it so you can install the new one the same way.
  • After inserting the new battery, press the two halves together firmly until they click, then test the fob on your car before you leave the store.

What battery your Hyundai key fob needs

The battery type is printed on the old battery itself once you open the fob, so the easiest way to know what to buy is to open it first and look. Most Hyundai fobs from the last 15 years use a CR2032 (the most common size) or a CR2025 (slightly thinner). Some older or specialty fobs may use a CR2016 or CR2020, but these are less common.

If you want to know before you open the fob, check your owner's manual—it usually lists the battery type in the key fob section. You can also call your Hyundai dealer with your vehicle identification number (VIN) and model year, and they will tell you. Once you know the type, buy a fresh battery from a pharmacy, grocery store, or hardware store; they are all the same regardless of brand, so the cheapest option is fine.

How to open the key fob

Look at the seam that runs around the edge of your key fob where the two halves meet. You will see a small slot or groove on one side—this is where you insert a coin. Use a flat coin (a penny, dime, or quarter works) and gently insert it into the slot, then twist it slightly as if you were opening a battery compartment on a remote control. You are not forcing it; a small twist is enough to separate the two halves.

Once the halves start to separate, you can usually pull them apart by hand. Be gentle—the plastic clips that hold the fob together are small and can break if you yank too hard. If it feels stuck, twist the coin a bit more rather than pulling harder. The two halves should come apart cleanly, and you will see the battery sitting in a small metal holder in the center.

Removing and replacing the battery

Before you take the old battery out, look at which side is facing up—the positive side (marked with a + symbol) or the negative side (marked with a − symbol). This matters because the new battery must go in the same way. Most Hyundai fobs have the positive side facing up, but check yours to be sure.

Gently pry the old battery out of its metal holder using the edge of your coin or a plastic tool (a credit card edge works too). Do not use a sharp metal tool that could damage the holder. Once the old battery is out, drop the new battery into the holder with the same side facing up as the old one was. The battery should sit flat and snug in the holder without any wiggling.

Closing the fob and testing it

Line up the two halves of the fob so the seams match, then press them together firmly. You should hear or feel a small click as the plastic clips snap back into place. If the halves do not want to come together, check that the battery is sitting flat in its holder and not sticking up at an angle.

Before you leave the store or drive away, test the fob on your car. Press the lock and unlock buttons and watch your car's lights or listen for the locks to respond. If the fob works, you are done. If it does not work, go back inside and try a different battery of the same type—occasionally a battery is dead on arrival, though this is rare.

What to do if the fob still does not work

If you installed a fresh battery and the fob still does not respond, the problem is usually not the battery. The fob may have a dead circuit board, a broken button, or water damage inside. Check that the battery is installed correctly—positive side up, sitting flat in the holder, and the fob is fully closed. If all of that is correct and the fob still does not work, the fob itself needs to be replaced.

You can buy a replacement fob online or from a Hyundai dealer. Dealer fobs are more expensive but come programmed to your car. Online fobs are cheaper but require programming, which a dealer or a locksmith can do for you. If you have a spare fob that works, you know the problem is with the one you just opened, not with your car's receiver.

Storing old batteries safely

Once you have removed the old battery, do not throw it in the trash. Coin-cell batteries contain chemicals that can leak into soil and water. Most pharmacies and stores that sell batteries have a battery recycling bin near the checkout or customer service desk—just drop the old one in.

If your store does not have one, check Earth911.com or call your local waste management office to find a recycling location near you. Many communities also accept batteries at hazardous waste collection events held a few times per year. Taking a few seconds to recycle the old battery keeps it out of landfills and protects groundwater.

Frequently Asked Questions

Can I use any CR2032 battery, or does it have to be a Hyundai brand?

Any CR2032 battery works the same way. Brand does not matter—a battery from a pharmacy, a grocery store, or an electronics shop will work just as well as one from a dealer. Buy whichever is cheapest and freshest.

What if I cannot get the fob open with a coin?

Try a different coin—a dime or penny sometimes works better than a quarter depending on the slot width. If the fob is very stuck, try inserting the coin at a different point along the seam. If it still will not budge, a locksmith or Hyundai dealer can open it for you, though this costs more than doing it yourself.

How often do I need to replace the battery?

Most key fob batteries last two to four years depending on how often you use the fob. If your fob starts to work only when you hold it close to the car, or if you have to press the button multiple times, the battery is probably dying and should be replaced soon.

Will replacing the battery erase my car's settings or require reprogramming?

No. Changing the battery in the fob does not affect your car's memory or settings. The fob will work exactly as it did before once the new battery is installed. No reprogramming is needed.