You can replace a Hyundai key fob battery yourself in about two minutes with a coin and a replacement battery
Most Hyundai key fobs use a coin-cell battery — typically a CR2032 or CR2025 — that you can buy at any pharmacy, grocery store, or hardware store for a few dollars. The fob itself is designed to open without tools; you use a coin to gently pry the two halves apart, swap out 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 the replacement.
The exact battery type depends on your Hyundai model year and fob design, so before you buy, check your owner's manual or look at the battery compartment itself — the battery type is usually printed inside. If you cannot find it, a Hyundai dealer can tell you over the phone with your vehicle identification number (VIN), which is on your registration or dashboard.
Key Takeaways
- Hyundai key fobs use replaceable coin-cell batteries, most commonly CR2032 or CR2025, available at drugstores and supermarkets for under five dollars.
- You open the fob by inserting a coin into the slot on the edge and gently twisting to separate the two halves without forcing them.
- Note which side of the battery faces up before you remove it, then insert the new battery the same way and press the halves back together until they click.
- If your fob still does not work after the battery replacement, the problem is likely a worn contact or a damaged circuit board, not the battery itself.
What battery type your Hyundai key fob needs
The battery type is printed on the inside of your fob or in your owner's manual. CR2032 is the most common size for recent Hyundai models, but some older fobs and certain trim levels use CR2025 or CR2016. The numbers refer to the battery's diameter and thickness — CR2032 is 20 millimeters across and 3.2 millimeters thick — so using the wrong size will not fit or will not make good contact.
If you open the fob and see the battery already inside, you can straightforward read the code printed on it. If you do not want to open it first, call your Hyundai dealer with your VIN and model year, and they will tell you the correct battery in under a minute. You can also check the fob's battery compartment at a pharmacy — most staff can identify the battery type by sight if you bring the fob in.
How to open your key fob safely
Look for a small slot or seam running around the edge of your fob where the two halves meet. Insert a coin — a dime or penny works well — into the slot and gently twist it as if you are opening a jar lid. You are not forcing it; you are just explore steady pressure to separate the two plastic halves. If it does not budge after a few seconds of gentle twisting, try a different spot along the seam — sometimes one side opens more easily than the other.
Once you feel it start to give, you can usually finish by hand. Pry the two halves apart slowly and set one half aside on a clean surface. Be careful not to lose the small spring or contact pad that may be sitting inside — these are straightforward to drop and hard to find on a floor. If anything falls out, pick it up right away and note where it was positioned.
Removing the old battery and installing the new one
Before you touch the old battery, look at which side is facing up — the positive side is usually marked with a plus sign or is straightforward the shiny side. Gently pry the old battery out with your fingernail or the edge of a coin. Do not use a sharp tool that could scratch the battery compartment or damage the contact points inside.
Slide the new battery in the same orientation as the old one — positive side up, unless the compartment clearly shows otherwise. Press down gently until the battery sits flat and makes contact with the metal points on both sides. Then line up the two halves of the fob and press them together until you hear or feel a click. The fob should snap together firmly; if it feels loose, open it again and make sure the battery is seated all the way down.
Testing your fob after battery replacement
Stand a few feet from your Hyundai and press each button on the fob — lock, unlock, panic, trunk, or whatever buttons yours has. You should see the lights flash on your vehicle and hear the locks respond. If nothing happens, open the fob again and check that the battery is making contact on both sides and is facing the right direction.
If the fob still does not work after you have tried a fresh battery in the correct orientation, the problem is likely inside the fob itself — a corroded contact point, a cracked circuit board, or a worn button. At that point, a replacement fob from a Hyundai dealer is usually the next step. A dealer can also program a new fob to your vehicle if you buy one.
Where to buy replacement batteries
CR2032 and CR2025 batteries are stocked at nearly every pharmacy, supermarket, and drugstore in the battery aisle. Walmart, Target, CVS, Walgreens, and local grocery stores all carry them. You can also order them online from Amazon or other retailers, though buying in person means you can test your fob the same day. A single battery usually costs between one and three dollars; a pack of two or four costs only slightly more, so buying extras is practical if you have multiple fobs.
Some Hyundai dealers sell batteries as well, but you will pay more — usually five to ten dollars — for the same battery you can get elsewhere for a dollar or two. Unless you are already at the dealer for another reason, buying from a pharmacy or supermarket is faster and cheaper.
When to replace your key fob battery versus the whole fob
A battery replacement is the right move if your fob is otherwise in good condition — no cracks, no missing buttons, and the buttons click when you press them. If the fob has been dropped, sat on, or exposed to water, or if the buttons feel mushy or do not click, the battery may not be the problem. Water damage and physical damage usually require a new fob rather than just a new battery.
If you have replaced the battery twice in the last year and the fob keeps dying, that is unusual and suggests the fob is draining the battery faster than normal — a sign of an internal short or a failing circuit. In that case, a new fob is more reliable than repeated battery replacements. A Hyundai dealer can order a replacement fob and program it to your vehicle in about an hour.
Frequently Asked Questions
Can I use a different battery size if I cannot find the exact one?
No. A CR2032 and a CR2025 look similar but are different thicknesses, and using the wrong one means the battery will not make proper contact with the metal points inside the fob. Your fob will not work, or will work only intermittently. Always use the exact battery type your fob is designed for.
How long does a key fob battery usually last?
Most coin-cell batteries in key fobs last two to four years with normal use. If you use your fob many times a day, the battery may wear out sooner. If you rarely use it, it may last longer. Batteries also lose power over time even when not in use, so an old fob that has been sitting in a drawer may need a fresh battery even if you have not used it much.
What do I do if I lost one of the halves of my fob?
If the plastic casing is cracked or a half is missing, you need a replacement fob. A Hyundai dealer can order one and program it to your vehicle. You cannot repair a broken fob casing yourself, and a fob without a proper seal will eventually let moisture inside and damage the circuit board.
Will replacing the battery erase my fob's programming?
No. The battery powers the fob, but the programming that links it to your vehicle is stored in a separate chip inside the fob. Changing the battery does not touch that programming, so your fob will work exactly as it did before once the new battery is in place.
Can I clean the battery contacts while I have the fob open?
Yes. If the metal contact points inside the fob look dark or corroded, gently rub them with a clean, dry cloth or a pencil eraser. Corrosion can prevent the battery from making good contact, so cleaning the contacts sometimes fixes a fob that seemed dead. Let any moisture dry completely before you close the fob back up.