Most Honda key batteries are CR2032 or CR2025 cells you can swap yourself in under a minute

Honda key fobs use coin-cell batteries — usually CR2032 or CR2025 — that sit in a small compartment inside the fob itself. You do not need a dealer or special tools. The battery slides out, you drop in a new one, and the fob works again. The whole job takes longer to find the battery at a store than to install it.

The exact battery type depends on your Honda model year and which fob you have. Older Hondas and some current models use CR2032; some newer fobs use CR2025. Both cost between $3 and $8 at any pharmacy, grocery store, or hardware store. If you are not sure which one your fob needs, you can open it first and read the number printed on the old battery, or check your owner's manual.

Key Takeaways

  • Honda key fobs use CR2032 or CR2025 coin-cell batteries that you can buy at any pharmacy or grocery store for a few dollars.
  • You open the fob by sliding a flat tool into the seam between the two halves, then swap the old battery for the new one with the positive side facing up.
  • The battery type is printed on the old cell itself, so if you are unsure, open the fob and read it before you buy a replacement.
  • If the fob still does not work after you install a fresh battery, the problem is likely a worn button contact or a dead circuit board, not the battery itself.

How to open your Honda key fob

Look at the seam that runs around the edge of your fob where the two plastic halves meet. You will see a small slot or groove on one side. Slide a flat tool — a coin, a flathead screwdriver, or a plastic pry tool — into that slot and gently twist or pry. The two halves will separate. Do not force it; if it does not budge, you are probably in the wrong spot.

Once the fob is open, you will see the battery sitting in a small metal holder. The battery is round and flat, about the size of a dime. Note which side is facing up — that matters when you put the new one in. The positive side (marked with a + symbol) should face toward you, not away.

Removing the old battery and installing the new one

Slide the old battery out of its holder with your fingernail or a plastic tool. Do not use a metal tool that could scratch the circuit board. Once it is out, check the number printed on it — that is your battery type. If you do not have the new battery yet, write down the number or take a photo.

Slide the new battery into the holder with the positive side facing up. It should sit flat and click into place. If it feels loose or sits crooked, remove it and try again. The battery should not require force; it should slide in smoothly and sit flush with the holder.

Closing the fob and testing the buttons

Press the two halves of the fob back together until they snap. You should hear or feel a click. Do not force them; they should come together easily once they are aligned. If they do not close smoothly, open it again and make sure the battery is sitting flat and the circuit board is not bent.

Test each button on the fob — lock, unlock, panic, trunk release, or whatever buttons yours has. Hold each one for a second and listen for the click of the lock or watch for the lights on your car to respond. If the buttons work, you are done. If they do not, the battery may not be making good contact; open the fob again and reseat it.

What battery type does your Honda use

CR2032 is the most common battery in Honda key fobs across model years. It is 20 millimeters in diameter and 3.2 millimeters thick. CR2025 is slightly thinner (2.5 millimeters) and is used in some newer Honda models and some aftermarket fobs. Both are 3-volt lithium cells and cost roughly the same.

If you open your fob and the battery is not labeled clearly, or if you want to know before you open it, check your owner's manual. Search for "key fob battery" or "remote battery" in the index. You can also call a Honda dealership parts department with your vehicle identification number (VIN) and model year, and they will tell you which battery your fob uses. Many dealerships will also sell you the battery for $5 to $10, though a pharmacy or hardware store is usually cheaper.

When a new battery does not fix the problem

If you install a fresh battery and the fob still does not work, the issue is not the battery. The most common culprit is worn rubber button contacts inside the fob. Over time, the conductive coating on the rubber pads wears away, and the buttons stop sending a signal even though the battery is fine. You can sometimes restore them by cleaning the contacts with rubbing alcohol and a cotton swab, but if that does not work, the fob needs replacement.

A second possibility is a dead or damaged circuit board. If the fob was dropped, exposed to water, or sat unused for years, the board itself may have failed. In that case, you will need a replacement fob. Honda dealerships sell OEM fobs, and aftermarket fobs are available online. Prices range widely depending on whether you want a basic remote or one with extra features.

Where to buy replacement batteries

CR2032 and CR2025 batteries are sold everywhere: pharmacies like CVS and Walgreens, grocery stores, hardware stores like Home Depot and Lowe's, and online retailers like Amazon. A single battery usually costs $3 to $8. Some stores sell them in multipacks for $8 to $15, which is a better deal if you have multiple fobs or want spares on hand.

Make sure you are buying the correct type. Read the package label carefully — it should say CR2032 or CR2025, not some other number. If you are buying online, double-check the product title and description before you order. Counterfeit or mislabeled batteries are rare but do happen.

Frequently Asked Questions

How long does a Honda key fob battery last?

Most CR2032 and CR2025 batteries last three to four years in a key fob, depending on how often you use the fob. Heavy use — pressing the buttons many times a day — drains the battery faster. If you use your fob only a few times a week, it may last longer.

Can I use a different battery type if I cannot find the right one?

No. CR2032 and CR2025 are not interchangeable in most Honda fobs. Using the wrong size can cause the battery to sit loose, fail to make contact, or not fit at all. Buy the correct type for your fob. If you are unsure which one you need, open the fob and read the old battery, or call a Honda dealership.

What should I do with the old battery?

Lithium coin-cell batteries can be recycled. Many pharmacies and electronics stores have battery recycling bins near the checkout. You can also check Earth911.com or Call2Recycle.org to find a recycling location near you. Do not throw the battery in the trash.

Will replacing the battery reprogram my fob to my car?

No. Replacing the battery does not change the programming. Your fob is already programmed to your car, and a new battery will not erase that. If your fob was never programmed to your car, or if you need to reprogram it for some reason, that is a separate process and requires your car's ignition and a dealer or locksmith.

Can I damage my fob by opening it?

It is unlikely if you are careful. Use a plastic tool or coin rather than a sharp metal screwdriver, and do not force the halves apart. Avoid touching the circuit board with wet hands or metal tools. If you are nervous, a Honda dealership or locksmith can open and replace the battery for you, usually for $10 to $20 in labor.