You can change a Honda key fob battery yourself in under five minutes
Most Honda key fobs use a coin-cell battery — usually CR2032 or CR2025 — that you can swap out without tools or a trip to the dealer. The battery costs between $3 and $8 at any pharmacy, grocery store, or hardware store. You do not need to reprogram the fob after changing the battery; it will work when ready once the new battery is in place.
The exact steps depend slightly on which Honda model you own, but the process is nearly identical across all current and recent Honda vehicles. This guide covers the most common fob design. If your fob looks different — for example, if it has a flip key or a sliding battery cover — check your owner's manual for the specific method, or search for your model year and fob type online.
Key Takeaways
- Honda key fobs use CR2032 or CR2025 coin-cell batteries that cost $3 to $8 and are sold at drugstores and supermarkets.
- You can open most Honda fobs by locating the seam on the side, inserting a flat tool into the slot, and gently twisting to separate the two halves.
- The battery slides out or lifts straight up depending on the fob design; note which side faces up before you remove it so you install the new one the same way.
- No reprogramming is needed after you install a new battery — the fob will work as soon as you close it and press a button.
Locate the seam and open the fob
Hold the fob in your hand with the buttons facing you. Look at the edge where the two plastic halves meet — you will see a thin seam running around the perimeter. On most Honda fobs, one side of this seam has a small slot or notch cut into it. This is where you insert a flat tool to pry the fob open.
Use a flathead screwdriver, a coin, or a plastic pry tool. Insert it gently into the slot and twist slightly, as if you were opening a paint can. Do not force it; the two halves should separate with light pressure. Once you see a gap, you can use your fingernail or the tool to work around the seam and fully separate the front and back pieces.
Remove the old battery and note its position
Once the fob is open, you will see the battery sitting in a small metal or plastic holder. Before you touch it, look at which side is facing up — this matters because the battery only works one way. The side marked with a + (positive) should face the same direction in the new battery.
The battery either slides out horizontally or lifts straight up. If it slides, gently push it to one side until it pops free. If it lifts, use your fingernail or a plastic tool to pry it up slightly, then remove it by hand. Do not use a metal tool to pry if you can avoid it, as you might scratch the circuit board inside.
Insert the new battery the same way
Take your new CR2032 or CR2025 battery and check that the + side matches the direction the old battery was facing. If the old battery slid in from the side, slide the new one in the same way until you hear or feel a click. If the old battery lifted up, place the new one in the holder with the + side up and press gently until it sits flat.
Make sure the battery is fully seated in its holder. A loose battery will not make contact and the fob will not work. If the fob has a small metal clip or spring over the battery, make sure it is still in place and not bent.
Close the fob and test it
Line up the two halves of the fob so the seams match. Press them together firmly until you hear a click or feel them snap into place. The fob should be solid and not wobble or feel loose.
Press any button on the fob — lock, unlock, or panic — and point it at your Honda from a few feet away. The car should respond when ready. If it does not, open the fob again and check that the battery is fully seated and facing the correct direction. If the car still does not respond, the battery may be defective; try a different new battery before assuming the fob itself is broken.
Which battery type your Honda uses
Most Honda fobs from 2010 onward use a CR2032 battery, which is the most common coin-cell size. Some older models or certain fob designs use a CR2025, which is slightly thinner but the same diameter. Both are widely available and cost about the same.
If you are unsure which one your fob needs, check your owner's manual — it will list the battery type. You can also open the fob and look at the number printed on the old battery itself. If you buy the wrong size, it will not fit properly in the holder, so do not force it. Return it and get the correct one.
When to replace the battery again
A fresh coin-cell battery typically lasts two to four years in a key fob, depending on how often you use it. You will notice the fob is dying when you have to press the buttons harder or stand closer to the car for it to work. At that point, the battery is nearly dead and you should replace it soon.
Do not wait until the fob stops working entirely, because a completely dead battery can sometimes cause the fob to lose its programming on certain Honda models — though this is rare. If your fob ever stops working even after you install a fresh battery, the fob itself may be damaged and you will need to buy a replacement from Honda or a third-party supplier.
Frequently Asked Questions
Do I need to reprogram my key fob after changing the battery?
No. The battery change does not affect the fob's programming. Once you close the fob and press a button, it will work exactly as it did before. Reprogramming is only necessary if you buy a brand-new fob or if the fob loses its programming for another reason.
What if the fob still does not work after I put in a new battery?
First, open the fob again and make sure the battery is fully seated in its holder and facing the correct direction — the + side should match the original position. If it is, try a different new battery in case the first one was defective. If a second fresh battery does not work, the fob's circuit board or buttons may be damaged.
Can I use a rechargeable battery in my Honda key fob?
Rechargeable coin-cell batteries exist but are not recommended for key fobs. They hold less charge than disposable ones and may not provide enough power to transmit a signal reliably. Stick with a standard disposable CR2032 or CR2025 for consistent performance.
Where is the cheapest place to buy a replacement battery?
Drugstores like CVS and Walgreens, supermarkets, and hardware stores all carry CR2032 and CR2025 batteries for $3 to $8. Online retailers like Amazon are often cheaper per battery if you buy in bulk, but you will pay for shipping. For a single battery, a local store is usually faster and costs about the same.
Is it safe to open my Honda key fob myself?
Yes. The fob contains no dangerous components and opening it to change the battery will not damage it if you use gentle pressure and a plastic or soft tool. Avoid using sharp metal tools that could scratch the circuit board, and do not force the two halves apart — if it does not open easily, you may be prying at the wrong spot.