Keyless entry batteries are small coin cells that die every few years and cost $3 to $10 to replace
Your car's keyless entry remote runs on a coin-cell battery — usually a CR2032, CR2025, or similar — that lasts between three and four years depending on how often you use the fob. When the battery dies, the remote stops working at any distance, though your car's physical key still opens the door. Replacing it takes five minutes and costs less than a coffee at most places that sell batteries.
You do not need a dealer or a technician. The battery is accessible without tools in most cases, and the part itself is sold at pharmacies, grocery stores, hardware stores, and online retailers. The main decision is whether to buy the battery first and then open the fob, or open the fob first to see what battery you need.
Key Takeaways
- Keyless entry remotes use coin-cell batteries (CR2032 is most common) that last three to four years before needing replacement.
- You can open most fobs by hand or with a flat tool like a coin or screwdriver blade; no special equipment is required.
- The battery costs $3 to $10 and is sold at drugstores, supermarkets, and hardware stores without any paperwork.
- If the remote still does not work after battery replacement, the fob may need reprogramming or repair, which varies by car make.
How to identify which battery your fob uses
The battery type is printed on the inside of your remote fob. To find it, look for a seam or line running around the edge of the fob — this is where the two halves separate. Use a coin, flathead screwdriver, or your fingernail to gently pry the fob open along that seam. Most fobs pop apart without force; if you feel strong resistance, you are likely prying in the wrong spot.
Once open, you will see a small round battery sitting in a metal holder. The battery itself is stamped with a code like CR2032, CR2025, or CR2016. Write down this code or take a photo. If you cannot open the fob easily, check your car's owner manual — it usually lists the battery type in the remote control section.
Where to buy the replacement battery
Coin-cell batteries are stocked at most retail locations. Pharmacies like CVS and Walgreens carry them in the health and beauty section or near the checkout. Grocery stores stock them in the pharmacy or electronics aisle. Hardware stores like Home Depot and Lowe's have them in the electrical section. Online retailers like Amazon stock them in bulk at lower per-unit cost if you want extras.
Prices vary slightly by retailer and whether you buy a single battery or a pack. A single CR2032 typically costs $4 to $8 at a pharmacy; a pack of four costs $6 to $12 online. Dealerships also sell these batteries, usually at a markup of $8 to $15, so they are not the cheapest option unless you are already there for service.
Steps to replace the battery in your fob
Open the fob by prying gently along the seam with a coin or flat tool. Set the two halves on a clean surface so you do not lose the small spring or contact that may be inside. Note which side of the battery faces up — the positive side (marked with a + or a flat surface) should face outward toward you.
Lift the old battery out of its metal holder. If it is stuck, gently work a fingernail or plastic tool under the edge. Drop the new battery into the holder with the positive side facing the same direction as the old one faced. Close the fob by pressing the two halves together until they click or snap. Test the remote by pressing a button while standing near your car — the lights should flash or the door should unlock.
If the remote does not work after replacement, open the fob again and check that the battery is seated fully in the holder and facing the correct direction. If it still does not work, the fob may need reprogramming. Most cars allow you to reprogram a remote by turning the key to the "On" position without starting the engine, then turning it back to "Off" several times in quick succession. Your owner manual lists the exact steps for your car make.
When the battery replacement does not fix the problem
If a new battery does not restore the remote's function, the issue is usually not the battery itself. The most common cause is a worn-out button contact inside the fob — the rubber pad under each button can wear smooth over time and stop conducting electricity. This requires opening the fob and either cleaning the contact with a pencil eraser or replacing the rubber pad, which costs $10 to $30 if done by a dealer.
Less commonly, the circuit board inside the fob is damaged or the transmitter has failed. This is not repairable at home and requires a replacement fob from your dealer or a third-party remote supplier. Replacement fobs cost $50 to $200 depending on your car make and whether you buy from the dealer or an aftermarket source. Some aftermarket remotes are programmable by the owner; others require dealer programming.
Reprogramming your remote after battery replacement
Many cars do not require reprogramming after a straightforward battery change — the remote will work as soon as you close the fob. However, some vehicles, particularly older models and certain luxury brands, may need the remote to be reprogrammed to the car's receiver after the battery has been dead for a long time.
The reprogramming process varies by manufacturer. For most domestic cars, sit in the driver's seat with the doors closed, insert the key into the ignition, and turn it to the "On" position without starting the engine. Turn it back to "Off." Repeat this cycle four to six times until you hear a chime or see the lights flash. Then press any button on the remote to confirm programming. Check your owner manual for the exact sequence for your vehicle, as some brands use different steps.
Frequently Asked Questions
What happens if I put the battery in backwards?
The remote will not work, but the battery will not be damaged. straightforward open the fob again and flip the battery so the positive side (marked with a +) faces outward. This is the most common mistake and is easily fixed.
Can I use a different battery type if I cannot find the exact one?
No. Different coin-cell batteries have different voltages and sizes. Using the wrong type can damage the fob's circuit board or not fit in the holder at all. Buy the exact type printed on your old battery or listed in your owner manual.
How long does a keyless entry battery last?
Most coin-cell batteries last three to four years in a car remote. Heavy users who press the fob many times per day may need replacement sooner; light users may get four to five years. There is no way to predict exactly when yours will die.
Do I need to reprogram my remote after replacing the battery?
Most cars do not require reprogramming after a battery change. However, if your remote does not work after you install the new battery, check your owner manual for the reprogramming steps specific to your vehicle make and model.
Can I replace the battery myself or do I need a dealer?
You can replace it yourself in five minutes with no special tools. Dealers will do it for you, usually charging $15 to $50 in labor plus the cost of the battery, but there is no advantage to paying for this service unless you are already at the dealership.