What you need before you start
Ford key fob batteries are standard coin cells — usually CR2032, CR2025, or CR2016 depending on your model year and fob style. You can buy a replacement at any pharmacy, grocery store, or dollar store for between $3 and $8. You will also need a small flathead screwdriver or a coin to pry the fob open; a butter knife works if you are careful.
Check your owner's manual or search your vehicle's year and model online to confirm which battery size your fob uses. The battery type is usually printed on the old battery itself once you open the fob, so if you are not sure, you can open it first, look at the dead battery, and go buy the right replacement.
Key Takeaways
- Ford key fob batteries are coin cells (CR2032, CR2025, or CR2016) that cost $3 to $8 and are sold at pharmacies and grocery stores.
- Most Ford fobs open by inserting a flathead screwdriver or coin into a slot on the edge and twisting gently to separate the two halves.
- The battery sits in a small metal holder; note which side faces up before you remove it, then drop the new battery in the same way.
- Snap the fob halves back together and test all buttons before you put the old battery in the trash.
- If the fob still does not work after a new battery, the problem is usually a corroded contact or a broken button, not the battery itself.
Opening your Ford key fob
Look at the edge of your fob for a small slot or seam. Most Ford fobs have a slot on one long edge where the two plastic halves meet. Insert a flathead screwdriver or the edge of a coin into that slot and twist gently — do not force it. The two halves should separate with light pressure.
If your fob has no visible slot, look for a small button or latch on the back. Some older Ford models have a release button you press while pulling the halves apart. Check your owner's manual if you cannot find the opening point; forcing a fob that opens a different way will crack the plastic.
Removing and replacing the battery
Once the fob is open, you will see the battery sitting in a small metal holder or clip. The battery is round and flat, about the size of a dime. Before you touch it, note which side is facing up — the positive side (marked with a + symbol) should face the same direction in the new battery.
Gently pry the old battery out with your fingernail or the tip of your screwdriver. Drop the new battery into the holder with the positive side facing the same direction as the old one faced. The battery should sit flat and snug in the holder; if it falls out when you tilt the fob, you have it upside down.
Closing the fob and testing
Align the two halves of the fob so the seams match up evenly. Press them together firmly until you hear or feel a click. The fob should close smoothly; if it feels stuck or the halves do not line up, open it again and check that the battery is sitting flat in its holder.
Test each button on the fob — lock, unlock, panic, trunk, or whatever buttons your model has. Walk to your car and press the buttons from a distance to confirm the fob is working. If all buttons work, you are done. Throw away the old battery in the trash; do not flush it.
What to do if the new battery does not work
If the fob still does not work after you install a new battery, the problem is usually not the battery. Check that you installed it with the positive side facing the correct direction. If you are not sure which way is correct, remove the battery, flip it, and try again.
If flipping the battery does not help, look inside the fob for corrosion — a white, green, or blue crusty buildup on the metal contacts. If you see corrosion, rub the contacts gently with a pencil eraser or a small piece of fine sandpaper, then reinstall the battery. If the fob still does not work and you see no corrosion, one of the buttons or internal circuits may be broken, and the fob will need to be replaced rather than repaired.
How long a Ford key fob battery lasts
A new coin cell battery in a Ford key fob usually lasts between three and four years with normal use. Heavy use — pressing the buttons many times a day — can shorten that to two years. Cold weather does not damage the battery, but it can make it perform poorly temporarily; a battery that seems dead in winter may work again when it warms up.
You will notice the fob starting to fail before the battery is completely dead. Buttons may require multiple presses, or the fob may only work from very close to the car. When you see those signs, replace the battery. A fob that has stopped working entirely may have a dead battery, but it could also have a broken button or corroded contacts, so do not assume a replacement battery will fix it.
Frequently Asked Questions
Can I replace a Ford key fob battery myself or do I have to go to the dealer?
You can replace it yourself in about five minutes with a screwdriver and a battery from any store. The dealer will do it for you for $50 to $150, but there is no reason to pay that when the job is this straightforward. The only exception is if your fob is broken or corroded inside; in that case, the dealer can sell you a new fob.
What if I put the battery in upside down?
The fob will not work, but you will not damage anything. straightforward open the fob again, flip the battery, and close it. The positive side (marked with a +) should face up toward the button side of the fob in most models, but if you are not sure, try it one way, and if it does not work, flip it and try again.
Where can I buy a Ford key fob battery?
Any pharmacy, grocery store, dollar store, or big-box retailer sells coin cell batteries in the watch or battery section. You can also order them online. Prices range from $3 to $8 per battery. Buy a pack of two or three so you have a spare when the next one dies.
Is it safe to throw away the old battery in the trash?
Coin cell batteries are small and low-risk, and most municipalities allow them in household trash. If your area has a battery recycling program, you can drop it off there instead. Do not flush it down the toilet or leave it where children or pets can swallow it.
Why does my fob work sometimes but not other times?
This usually means the battery is dying but not completely dead yet. Replace it with a new one. If the new battery does not fix the problem, the issue is likely corroded contacts inside the fob or a worn button. Clean the contacts with an eraser and try again; if that does not work, the fob may need to be replaced.