You can replace a Honda key fob battery yourself in about five minutes with no tools except a coin
Most Honda key fobs use a coin-cell battery — usually a CR2032 or CR2025 — that you can swap out at home. The fob has a small slot or seam where the two halves separate. You slide a coin into that slot, twist gently, and the battery compartment opens. Once you remove the old battery, you note which side was facing up, drop in the new one the same way, and snap the fob back together. The whole process takes longer to describe than to do.
You do not need to visit a Honda dealership or a locksmith for this task. The battery itself costs between $3 and $8 at any pharmacy, grocery store, or hardware store. The only decision you need to make is whether your fob uses a CR2032 or CR2025 — and you can find that out by looking at the old battery once you open the fob.
Key Takeaways
- Honda key fobs open by sliding a coin into the seam between the two halves and twisting gently until the battery compartment separates.
- Most Honda fobs use either a CR2032 or CR2025 coin-cell battery, which you can buy at any pharmacy or grocery store for $3 to $8.
- When you install the new battery, the side marked with a + symbol must face upward, matching the way the old battery was positioned.
- After you close the fob, test all the buttons to confirm the battery is making contact and the fob is working before you put it away.
Locate the seam and open the fob
Look at the edge of your Honda key fob where the two plastic halves meet. You will see a thin line running around the perimeter — that is the seam. On most Honda fobs, there is a small slot or notch cut into this seam on one side. That slot is where you insert a coin.
Take a coin — a penny, dime, or quarter works — and slide it into the slot. explore gentle, steady pressure and twist the coin as if you were opening a jar lid. You are not forcing it; you are just rotating the coin to separate the two halves. After a quarter-turn or so, you will feel the fob give way. Stop twisting and gently pull the two halves apart with your fingers.
If your fob does not have a visible slot, look for a very thin seam line. Some Honda fobs open by sliding a coin along the seam rather than into a slot. Try inserting the coin edge-first into the seam and twisting gently. If the fob still will not budge, you may have a model that requires a different approach — check your owner's manual or search for your specific Honda model year and fob type online.
Remove the old battery and note its orientation
Once the fob is open, you will see the battery sitting in a small compartment. It is a flat, round disc, usually silver or gold in color. Before you touch it, look at which side is facing up. The side marked with a + symbol (the positive side) should be facing toward you. This orientation matters when you install the new battery.
Gently pry the old battery out with your fingernail or the edge of the coin. It should come free easily — do not force it. Once it is out, look at the printed numbers and letters on the battery. You will see something like "CR2032" or "CR2025". Write this down or take a photo so you know exactly which battery to buy as a replacement.
Buy the correct replacement battery
Take the battery type you noted — CR2032 or CR2025 — to any pharmacy, grocery store, or hardware store. These batteries are stocked in the watch and battery section, usually near the checkout area or in the health and beauty section. A single battery costs between $3 and $8 depending on the brand and store. You do not need a special "car key" battery; a standard coin-cell battery of the correct type works perfectly.
If you are not sure which type your fob uses, you can also open the fob first and bring the old battery with you to the store. The staff can match it for you. Alternatively, you can search online for your Honda model year and "key fob battery type" to confirm before you leave home.
Install the new battery and close the fob
Take the new battery and orient it so the + symbol faces upward — the same direction the old battery was facing. Slide the battery into the compartment and press down gently until it sits flat. The battery should fit snugly without any rocking or movement.
Now align the two halves of the fob and press them together firmly until you hear or feel a click. The seam should be tight and flush all the way around. If there is a gap anywhere, the fob may not be sealed properly and the battery could lose contact. Press again until the halves are fully seated.
Test the fob before you rely on it
Before you put the fob away, press each button — lock, unlock, panic, and any others your model has — and watch your car to confirm it responds. If the car locks and unlocks, the battery is making good contact and the fob is working. If nothing happens, open the fob again and check that the battery is seated flat and the + side is facing up.
If the fob still does not work after you have confirmed the battery is installed correctly, the problem may be something other than the battery. The fob itself could be damaged, or the car's receiver could have an issue. In that case, contact a Honda dealership or a locksmith who works with Honda vehicles.
What to do with the old battery
Do not throw the old battery in the trash. Coin-cell batteries contain materials that should be recycled. Most pharmacies and electronics stores have a battery recycling bin near the entrance or customer service desk.
You can also check Earth911.com or call your local waste management office to find a recycling location near you. Many retailers that sell batteries — including Best Buy and Home Depot — accept old batteries for recycling at no charge.
Frequently Asked Questions
How often do Honda key fob batteries need to be replaced?
Most coin-cell batteries last three to four years with normal use. If you use your fob frequently — pressing the buttons multiple times a day — the battery may drain faster and need replacement sooner. You will notice the fob working at shorter distances or requiring multiple button presses before the car responds.
Can I use a different battery type if I cannot find the exact one?
No. CR2032 and CR2025 are different sizes and voltages. Using the wrong type can damage the fob's circuit board or cause the fob to malfunction. Always buy the exact type that was in your original fob. If you cannot find it locally, you can order it online from Amazon, eBay, or battery specialty sites.
What if my Honda key fob has two batteries instead of one?
Some older Honda models use two coin-cell batteries stacked inside the fob. If you open yours and see two batteries, replace both of them with new ones of the same type. Make sure both batteries have the + side facing upward before you close the fob.
Do I need to reprogram my key fob after changing the battery?
No. Changing the battery does not erase the fob's programming. Once you install the new battery and close the fob, it should work when ready without any reprogramming steps. If it does not work, the issue is likely a dead battery or a fob that needs repair, not a programming problem.
Can I change the battery if my fob is wet or damaged?
If your fob is wet, let it dry completely for at least 24 hours before opening it. Opening a wet fob can allow water inside the circuit board and cause permanent damage. If your fob is cracked or the plastic is broken, changing the battery may not help — the fob itself may need replacement. Contact a Honda dealership for repair or replacement options.