Replace a Honda key fob battery in five minutes with a coin and the right battery type
Most Honda key fobs use a coin-cell battery that you can swap yourself without tools or a trip to the dealer. The battery sits behind a removable cover on the back of the fob. You pry the cover open with a coin, note which way the old battery faces, drop in a new one the same way, and snap the cover back. The whole job takes about five minutes and costs between $3 and $8 for the battery.
The catch is knowing which battery your fob needs. Honda uses different types depending on the model year and fob design. A battery that fits one fob will not fit another. Before you buy, you need to open the fob and read the number printed on the old battery — or check your owner's manual, which usually lists it.
Key Takeaways
- Honda key fob batteries are coin-cell types (usually CR2032, CR2025, or CR2016) that cost $3 to $8 and last three to four years.
- You open the fob by sliding a coin into the slot on the back edge and twisting gently until the cover pops off.
- The battery sits in a metal holder with a plus sign facing up; note this before you remove the old one so you install the new one the same way.
- Your owner's manual lists the correct battery type for your model, or you can read the number on the old battery itself.
- If the fob still does not work after you install a new battery, the problem is usually a worn button contact or water damage, not the battery.
Find out what battery your Honda fob needs
The fastest way is to open the fob and look at the old battery. The battery type is printed on its surface — usually CR2032, CR2025, or CR2016. Write down that number before you go to the store or order online.
If you want to know before opening the fob, check your owner's manual. Search the index for "key fob battery" or "remote battery." Most manuals list the type and sometimes the part number. You can also call a Honda dealer with your vehicle identification number (VIN) and model year, and they will tell you which battery fits.
Do not guess. A CR2032 and a CR2025 look nearly identical but have different thicknesses. Installing the wrong one can damage the battery holder or cause the fob to malfunction.
Open the key fob without breaking the cover
Look at the back of the fob. You will see a thin slot running along one edge — usually the bottom or side. This is where the cover separates from the body.
Insert a coin (a dime or penny works) into the slot. Turn the coin gently, as if you were opening a battery compartment on a toy or remote control. Do not force it. The cover should pop off or slide out after a quarter turn. If it does not budge, try a different spot along the slot — sometimes the cover is tighter on one side.
Once the cover is off, set it aside where you will not lose it. The battery sits in a metal holder inside. Do not touch the battery contacts or the metal holder with your bare fingers if you can avoid it — oils from your skin can interfere with the connection.
Remove the old battery and note its position
Look at the battery holder. One side has a plus sign (+) printed or embossed on it. The other side is blank or has a minus sign (−). The old battery is sitting with one side facing up toward that plus sign.
Before you remove the battery, remember which side is facing up. This matters. The new battery must go in the same way, or the fob will not work.
Gently pry the battery out with your fingernail or the edge of the coin. It should come free easily. If it is stuck, try working it from the edge rather than the center. Once it is out, set it aside — you do not need it anymore, but do not throw it in the trash. Most pharmacies and electronics stores have battery recycling bins.
Install the new battery the same way the old one faced
Take the new battery out of its packaging. Hold it so you can see which side is the plus side (the flat, shiny side is usually plus; the domed side is usually minus, but check the battery itself to be sure).
Place the new battery into the holder with the plus side facing the same direction the old battery was facing. Press down gently until you hear or feel a small click. The battery should sit flat and snug in the holder.
If the battery does not sit flat or feels loose, remove it and check that you have the right battery type. A battery that is too thick or too thin will not seat properly.
Close the fob and test the buttons
Align the cover with the body of the fob. The slot should line up with the edge. Press or slide the cover back into place until it clicks or snaps shut. You may need to apply gentle pressure, but it should not require force.
Press each button on the fob — lock, unlock, panic, trunk, or whatever buttons your model has. Point the fob at your car from a few feet away and press lock. The car should respond with lights or a beep. If nothing happens, remove the cover again and check that the battery is seated correctly and facing the right direction.
What to do if the fob still does not work
If you installed a new battery and the fob still does not respond, the problem is usually not the battery. The most common causes are a worn button contact inside the fob or water damage to the circuit board.
Button contacts wear out over time, especially if you press the same button repeatedly. If only one button does not work, the contact for that button is likely worn. If no buttons work, water damage is more likely — perhaps from a spill or being left in a pocket during rain.
A Honda dealer can replace the button contacts or the entire circuit board, but this usually costs $100 to $200. For many people, buying a replacement fob from the dealer or an aftermarket supplier is cheaper. If your car is still under warranty, the dealer may replace the fob for free.
Frequently Asked Questions
How long does a Honda key fob battery last?
Most coin-cell batteries last three to four years with normal use. If you use the fob heavily — pressing buttons many times per day — the battery may drain faster. A battery that dies after one year usually means the fob has a drain problem, not a bad battery.
Can I use a different battery type if I cannot find the right one?
No. CR2032, CR2025, and CR2016 are different sizes and voltages. Using the wrong type can damage the fob's circuit board or cause the buttons to malfunction. Always use the type listed in your manual or printed on the old battery.
What if I lose the cover when I open the fob?
Honda dealers sell replacement covers, usually for $10 to $20. You can also find aftermarket covers online. Without the cover, the battery will fall out and the fob will not work. Do not try to tape it closed — the tape will interfere with the battery connection.
Do I need to reprogram the fob after changing the battery?
No. Changing the battery does not erase the fob's programming. It will work immediately after you install the new battery. If the fob does not work after a new battery, reprogramming will not fix it — the problem is hardware, not software.
Where can I buy a Honda key fob battery?
Pharmacies, grocery stores, hardware stores, and electronics retailers all carry coin-cell batteries. You can also order them online. Prices are the same everywhere — usually $3 to $8 for a single battery. Buy two if you have multiple fobs, since they all use the same type.