Your Honda key fob battery usually lasts three to four years before it stops holding a charge

When your Honda key fob stops locking or unlocking your car from a distance, the battery inside is almost always the culprit. The battery is a small coin-shaped cell, typically a CR2032 or CR2025, that you can replace yourself in under a minute without tools or a trip to the dealer. The whole job costs between $3 and $8 for the battery itself.

You do not need to know your car's year or model in advance — the battery type is printed on the old battery once you open the fob. If you are uncomfortable opening the fob or if the fob itself is cracked, a Honda dealership or a local locksmith can do it for you, usually for $15 to $50 in labor.

Key Takeaways

  • Honda key fob batteries are coin-shaped cells (usually CR2032 or CR2025) that cost $3 to $8 and last three to four years on average.
  • You can open most Honda fobs by inserting a flat object into the seam and gently twisting, without needing a screwdriver or special tools.
  • The battery type is stamped on the old battery itself, so you know exactly what to buy before you leave home.
  • If your fob still does not work after replacing the battery, the problem is likely the fob's circuit board or buttons, not the battery.

How to open your Honda key fob

Most Honda fobs have a seam running around the edge where the two plastic halves meet. Look for a small slot or groove in this seam — this is where you insert a flat object to pry the fob open. A coin, a flathead screwdriver, or even a butter knife works. Insert it gently into the slot and twist slightly, as if you were opening a can. The two halves should separate without force.

Some newer Honda fobs have a small button or latch on the back instead of a seam. Press or slide this button and the battery compartment will pop out or the fob will split open. If you cannot find either a seam or a button, check your owner's manual or search online for your specific model year — a small number of Honda fobs have a different design.

Once the fob is open, you will see the battery sitting in a small metal holder or slot. Note which side is facing up (the positive or negative side) before you remove it. The battery usually lifts out easily with your fingernail or a plastic tool.

Removing the old battery and installing the new one

Before you buy a replacement, look at the old battery. The type is stamped on the flat surface — you will see something like "CR2032" or "CR2025". Write this down or take a photo so you know exactly what to buy. These batteries are sold at drugstores, supermarkets, electronics stores, and online retailers.

When you have the new battery, insert it into the same slot with the same side facing up as the old one was. If the positive side (marked with a + or a flat surface) was facing up before, keep it facing up. The battery should sit flat and click into place. Do not force it — if it does not fit easily, you may have it upside down.

Close the fob by pressing the two halves together until you hear or feel a click. Test the lock and unlock buttons from a few feet away from your car. If the fob works, you are done. If it does not, try opening the fob again and flipping the battery to the opposite side — you may have installed it backwards.

Where to buy Honda key fob batteries

CR2032 and CR2025 batteries are among the most common coin-cell batteries made. You can find them at any pharmacy (CVS, Walgreens), any supermarket with a pharmacy section, Best Buy, Target, Walmart, and dozens of online retailers. A single battery usually costs $3 to $8. Buying a pack of two or four is often cheaper per battery than buying one.

If you do not want to replace the battery yourself, a Honda dealership will do it for you. Call ahead to ask the price — most dealerships charge $15 to $50 in labor, plus the cost of the battery. A local locksmith who works on car keys can often do it faster and cheaper than a dealership.

What to do if a new battery does not fix the problem

If you have replaced the battery and the fob still does not work, the problem is not the battery. The most common causes are water damage inside the fob, worn-out buttons, or a damaged circuit board. Water damage happens when the fob gets wet and the moisture corrodes the metal contacts inside. Worn buttons happen over time as you press them thousands of times.

If the fob is water-damaged, you can try opening it, letting the inside dry for 24 hours in a warm place (not in direct heat), and reassembling it. If the buttons are worn or the circuit board is damaged, the fob usually needs to be replaced. A new OEM (original equipment manufacturer) Honda fob costs $150 to $400 depending on the model, though aftermarket fobs are cheaper.

Before you buy a new fob, test your spare key fob if you have one. If the spare works, you know the problem is the fob itself. If the spare does not work either, the problem may be your car's receiver, not the fobs — in that case, take your car to a Honda dealership for diagnosis.

Programming a new or repaired fob to your car

If you replace just the battery in your existing fob, no programming is needed — the fob will work as soon as you close it. The fob was already programmed to your car when it was made.

If you buy a new fob (either OEM or aftermarket), it will need to be programmed to your car before it will work. Some Honda models allow you to program a new fob yourself using a sequence of steps with the ignition and door locks, but the exact steps vary by year and model. Your owner's manual will have these steps if they are available for your car. If your car does not support self-programming, a Honda dealership or a locksmith can program the new fob for you, usually for $50 to $150.

Frequently Asked Questions

How do I know if my Honda key fob battery is dead?

The most obvious sign is that the lock and unlock buttons stop working from a distance, though the buttons may still work if you hold the fob very close to the car. Some fobs have a light that dims as the battery dies. If the buttons feel mushy or do not click, the problem is likely worn buttons, not a dead battery.

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

CR2032 and CR2025 are slightly different sizes and voltages. Using the wrong one may cause the fob to work poorly or not at all. Buy the exact type stamped on your old battery. If you cannot find it, a Honda dealership or locksmith can tell you the correct replacement.

Will replacing the battery erase my car's settings or require me to reprogram anything?

No. Replacing the battery in an existing fob does not erase any programming or settings. The fob will work exactly as it did before, as soon as you close it and the battery makes contact.

What should I do with the old battery?

Coin-cell batteries contain small amounts of toxic materials and should not go in the trash. Most pharmacies and electronics stores have battery recycling bins near the checkout. Some accept them for free; others may charge a small fee.

Can I replace the battery in a Honda fob that is cracked or damaged?

If the crack is small and the fob still closes, you can try replacing the battery yourself. If the fob is severely cracked or will not close properly, opening it may make the damage worse. A locksmith or dealership can replace the battery in a damaged fob, though they may recommend replacing the fob entirely if the damage is extensive.