You can replace a Honda key fob battery yourself in about five minutes with no tools
Most Honda key fobs use a coin-cell battery—usually a CR2032 or CR2025—that you can swap out at home without taking the fob apart or visiting a dealer. The battery sits in a compartment you open by sliding or prying a small panel on the back of the fob. Once you know which battery your fob uses and where to buy it, the whole job takes longer to find the battery in your junk drawer than to install it.
You do not need a screwdriver, a special tool, or a trip to a Honda service center. A replacement battery costs between $3 and $8 at any drugstore, supermarket, or hardware store. If your fob still does not work after you replace the battery, the problem is likely the fob itself or the receiver in your car, not the battery.
Key Takeaways
- Honda key fobs use CR2032 or CR2025 coin-cell batteries that you can buy at any drugstore or supermarket for $3 to $8.
- The battery compartment opens by sliding or prying a small panel on the back of the fob—no screwdriver needed.
- Write down the old battery's part number before you remove it so you buy the exact same one.
- If the fob still does not work after you install a fresh battery, the fob receiver or the car's receiver may need service from a Honda dealer.
Find out which battery your Honda fob uses
The easiest way is to look at the battery you are about to remove. On the flat side of the battery, you will see a number stamped or printed on it—CR2032, CR2025, or occasionally CR2016. Write this number down before you take the old battery out. If you cannot read the number clearly, take a photo of it with your phone.
If you have lost the fob or the battery is too worn to read, check your Honda owner's manual. The manual lists the battery type for your model year and fob style. You can also call a Honda dealer with your vehicle identification number (VIN) and model year, and they will tell you the correct battery in under a minute.
Open the battery compartment on the back of the fob
Flip the fob over so the back is facing you. Look for a small seam or slot running along the edge of the back panel. This is where the two halves of the fob meet. On most Honda fobs, you will see a small notch or groove on one side of this seam.
Slide your fingernail or a plastic spoon handle into the groove and gently pry the back panel away from the fob body. Do not use a metal screwdriver or a sharp knife—you can crack the plastic or scratch the fob. The panel should pop off with light pressure. If it does not budge, try the other side of the seam; the notch is usually on one end.
Once the back panel is off, you will see the battery sitting in a small metal or plastic holder. The battery is usually held in place by a small spring or clip, or it may just rest loosely in the compartment.
Remove the old battery and install the new one
Gently lift the old battery out of its holder. If a spring or clip is holding it down, lift the spring or clip first, then slide the battery out. Do not force it; if it feels stuck, wiggle it gently side to side.
Before you install the new battery, check that the side facing up matches the old one. Coin-cell batteries have a flat positive side (marked with the battery number) and a flat negative side. The positive side should face up toward the back panel of the fob. Slide the new battery into the holder with the positive side up, then press the spring or clip back down if there is one.
Press the back panel of the fob firmly until you hear or feel a click. The panel should sit flush with the fob body with no gaps. Test the fob by pressing each button and listening for the click sound that means the transmitter is working.
Test the fob and troubleshoot if it still does not work
Stand near your car and press the lock and unlock buttons on the fob. You should hear the car lock or unlock, and you may see the lights flash. If the fob works right away, you are done.
If the fob still does not respond, try these steps: First, make sure the back panel is fully seated and the battery is installed with the positive side up. Second, remove the battery, wait 30 seconds, and reinstall it—this sometimes resets the fob's transmitter. Third, try the fob from different distances and angles; sometimes a weak receiver in the car needs you to be closer or pointed directly at it.
If none of these steps work, the problem is likely inside the fob itself (a broken button contact or failed circuit board) or the receiver in your car. At this point, you will need to contact a Honda dealer or a locksmith who programs key fobs. Do not buy another battery or fob until you have ruled out the receiver.
Where to buy replacement batteries
CR2032 and CR2025 batteries are among the most common coin-cell batteries made. You can find them at any of these places: drugstores (CVS, Walgreens), supermarkets (most have a pharmacy or health section), hardware stores (Home Depot, Lowe's, Ace), big-box retailers (Target, Walmart), and online (Amazon, eBay). A single battery usually costs $3 to $8 depending on the brand and where you buy it.
Buy a name-brand battery if you can—Energizer, Duracell, or Panasonic. Generic or store-brand batteries work fine and cost less, but name brands tend to last longer. Some stores sell them in multipacks, which is useful if you have multiple fobs or want spares on hand.
How often Honda key fob batteries need replacing
A fresh coin-cell battery in a key fob usually lasts between three and four years under normal use. If you use your fob several times a day, the battery may wear out sooner—in two to three years. If you use it rarely, it may last four years or longer.
You will notice the fob starting to fail before the battery is completely dead. The buttons may require harder presses, the range may shrink (you have to stand closer to the car), or the fob may work only intermittently. These are all signs the battery is running low. Replace it as soon as you notice these symptoms to avoid being locked out.
Frequently Asked Questions
Can I use a different battery size if I cannot find the exact one?
No. CR2032, CR2025, and CR2016 are different sizes and voltages, and using the wrong one can damage the fob or cause it to malfunction. Always use the exact battery type stamped on the old battery or listed in your owner's manual. If you cannot find the right battery locally, order it online—it will arrive in one or two days.
What should I do with the old battery?
Most retailers that sell batteries also collect old batteries for recycling. Take the old battery back to the store where you bought the new one and ask for their battery recycling bin. Do not throw it in the trash. Some pharmacies and electronics stores also have battery drop-off programs.
Will replacing the battery erase my car's settings or require reprogramming?
No. Replacing the battery in the fob does not affect your car's computer or settings. The fob will work when ready after you install the new battery. You do not need to reprogram it or visit a dealer.
Why does my fob work sometimes but not other times after I replaced the battery?
Intermittent fob operation usually means the battery is installed upside down (negative side up instead of positive), the back panel is not fully seated, or the fob's internal contacts are dirty or worn. Remove the back panel, check the battery orientation, clean the battery and contacts with a dry cloth, and reinstall it. If it still fails intermittently, the fob itself may be failing and will need replacement.
Can I replace the battery in a Honda smart key or push-button fob the same way?
Smart keys and push-button fobs use the same coin-cell batteries and open the same way. Follow the same steps: find the seam on the back, pry gently, remove the old battery, and install the new one with the positive side up. The process is identical to a standard remote fob.