You can replace a Honda key fob battery yourself in under five minutes
Most Honda key fobs use a coin-cell battery — typically a CR2032 or CR2025 — that you can swap out without tools or a trip to the dealer. The battery usually costs between $3 and $8 at any pharmacy, grocery store, or hardware store. You'll need to open the fob, remove the old battery, and slide in the new one. The whole job takes longer to find the battery in your junk drawer than to do the work.
The exact steps depend slightly on which Honda model you own and when it was made, but the principle is the same across nearly all of them: the fob splits into two halves, and the battery sits in a small metal holder inside.
Key Takeaways
- Honda key fobs almost always use a CR2032 or CR2025 coin-cell battery that you can buy at any drugstore or supermarket for $3 to $8.
- You do not need a screwdriver or special tools — most fobs open by sliding a small metal tab or prying gently at a seam with your fingernail.
- The battery holder is a small metal clip inside the fob; you lift one end of the clip to remove the old battery and slide the new one underneath.
- After you install the new battery, test the fob by pressing each button before you close it back up, so you know it works.
Find out which battery your Honda key fob needs
The easiest way is to open the fob and look at the old battery itself. The battery type is printed on the flat side — you'll see something like "CR2032" or "CR2025". Write that number down or take a photo with your phone, then buy the exact same type at a pharmacy, supermarket, or online.
If you don't want to open the fob first, you can also check your Honda owner's manual, which usually lists the battery type in the key fob section. If you've lost the manual, Honda's website has PDFs for most model years, searchable by year and model.
Do not guess at the battery type. CR2032 and CR2025 look nearly identical but have different thicknesses, and using the wrong one may prevent the fob from closing properly or cause poor contact inside the holder.
Open the fob without damaging the case
Most Honda fobs open one of two ways. The first is a small metal tab or slider on the edge of the fob — usually on the side or bottom. Slide it in the direction the arrow points (or away from the main body), and the two halves will separate. The second method is a seam running around the edge of the fob where the two halves meet. Use your fingernail or a plastic spoon handle to gently pry at that seam until the fob cracks open.
If you see a small screw on the back, you'll need a Phillips-head screwdriver to remove it before the fob opens. This is less common on newer Hondas but shows up on some older models.
Work slowly and gently. The plastic is thin, and forcing it can crack the case or snap the small tabs that hold the two halves together. If the fob won't budge after gentle pressure, stop and look again for a slider or button you may have missed.
Remove the old battery and install the new one
Once the fob is open, you'll see the battery sitting in a small metal holder — usually a clip with two prongs or a shallow cup. The battery sits flat, with the positive side (marked with a + symbol) facing up toward you.
To remove it, lift one end of the metal clip gently with your fingernail or a plastic spoon. The battery will pop out. If the clip is a cup rather than a clip, you may be able to straightforward lift the battery straight up.
Slide the new battery under the metal clip with the positive side facing up — the same way the old one was sitting. Press down gently until you hear or feel a small click, which means the clip is holding the battery in place. Do not force it; if it doesn't click, the battery may be upside down or the clip may not be seated properly.
Test the fob before closing it
While the fob is still open, press each button — lock, unlock, panic, trunk, or whatever buttons your fob has. You should see a small red or amber light flash inside the fob when you press a button. If you don't see a light, the battery may be installed upside down or the clip may not be making good contact.
If the light flashes, close the fob by pressing the two halves together until they snap. If you had to remove a screw, replace it now. Test the fob from inside your car to make sure the doors lock and unlock. If nothing happens, open the fob again and check that the battery is sitting flat and the clip is holding it firmly.
Where to buy a replacement battery
You can find CR2032 and CR2025 batteries at any pharmacy (CVS, Walgreens, Rite Aid), supermarket, or drugstore. They're usually in the electronics or watch battery aisle, sometimes near the checkout counter. A single battery costs $3 to $8, though multi-packs are often cheaper per battery if you buy several at once.
Hardware stores like Home Depot and Lowe's also stock coin-cell batteries. Online retailers like Amazon sell them in bulk, which makes sense if you have multiple fobs or devices that use the same battery type.
Avoid buying the cheapest generic brand if you can — name brands like Energizer, Duracell, and Panasonic tend to last longer and are only slightly more expensive. A Honda dealer can also replace the battery for you, but you'll pay $20 to $50 for labor on a job that takes five minutes.
What to do if the fob still doesn't work after replacing the battery
If you've installed a fresh battery and the fob still won't lock or unlock your car, the problem is usually not the battery. The most common cause is a worn-out button pad inside the fob — the rubber contact that presses against the circuit board when you push a button. Over time, the conductive coating on the pad wears away, and the button stops sending a signal even though the battery is fine.
A second possibility is water damage. If the fob has been dropped in water or exposed to moisture, the circuit board inside may be corroded, and a new battery won't fix it. You can try opening the fob and letting it dry in a warm, dry place for 24 hours, but if that doesn't work, the fob will need to be replaced.
If only one button works and the others don't, the problem is almost certainly the button pad, not the battery. If no buttons work and the fob is dry, the circuit board itself may be damaged. In either case, you'll need a new fob from Honda or an aftermarket supplier.
Frequently Asked Questions
Can I use a different battery type if I can't find the exact one?
No. CR2032 and CR2025 look nearly identical but have different thicknesses. Using the wrong one can prevent the fob from closing properly or cause the battery to lose contact with the clip. Always buy the exact type printed on your old battery.
How long does a Honda key fob battery last?
Most coin-cell batteries last three to four years in a key fob, depending on how often you use it. If you press the buttons dozens of times a day, the battery may wear out in two years. If you use the fob rarely, it may last five years or longer.
Do I need to reprogram my key fob after changing the battery?
No. Changing the battery does not erase any programming. Your fob will work exactly as it did before, as long as the new battery is installed correctly and the fob was working before the battery died.
What if I accidentally put the battery in upside down?
The fob straightforward won't work. The battery has a positive side (marked +) and a negative side. If you install it backwards, no current flows and the buttons won't send a signal. Open the fob, flip the battery over, and try again.
Can I replace the battery in a Honda smart key or push-button fob?
Yes, the process is the same. Smart keys and push-button fobs use the same coin-cell batteries as traditional key fobs. Open the fob the same way, swap the battery, and test the buttons before closing it back up.