You can replace an Acura key fob battery yourself in about five minutes with a coin and a replacement battery
Most Acura key fobs use a CR2032 coin cell battery that you can buy at any drugstore, supermarket, or hardware store for two to five dollars. The fob itself snaps open with a flathead screwdriver or coin — no tools beyond that are needed. The whole job takes longer to find the battery in your junk drawer than to do the swap.
The steps are the same whether you own a TSX, RDX, MDX, or any other current Acura model. The battery sits in a plastic holder inside the fob. You lift it out, note which side faces up, drop in the new one the same way, and snap the fob closed. If your key fob is older than ten years or the battery compartment looks corroded, you may need to clean the contacts before the new battery works.
Key Takeaways
- Acura key fobs use CR2032 batteries, which cost two to five dollars and are sold everywhere batteries are stocked.
- You open the fob by inserting a coin or flathead screwdriver into the slot on the edge and twisting gently until the two halves separate.
- The battery sits in a plastic holder and lifts straight out; install the new one with the positive side (marked with a plus sign) facing up, matching the old battery's position.
- If the fob does not work after you install the new battery, wipe the metal contacts inside the fob with a dry cloth or pencil eraser to remove corrosion.
Finding the battery slot on your Acura fob
Look at the edge of your key fob where the two plastic halves meet. You will see a small slot or seam running along that edge. This is where you insert your coin or screwdriver. The slot is usually on the side opposite the Acura logo or the side that faces your palm when you hold the fob normally.
If you cannot see a clear slot, run your fingernail or a coin along the seam. You are looking for a spot where the plastic gives slightly — that is the opening point. Some Acura fobs have a tiny arrow or line printed near the slot to show you which direction to turn.
Opening the fob without breaking the plastic
Insert a flathead screwdriver or the edge of a coin into the slot. A dime or penny works better than a quarter because it fits more snugly. Push gently and twist clockwise or counterclockwise — you will feel which direction the fob wants to go. Do not force it; if you meet hard resistance, you are probably twisting the wrong way.
The two halves will separate with a small click. If the fob is stuck, try tapping the screwdriver gently with a hammer to nudge it into the slot more deeply, then twist again. Avoid prying hard with a screwdriver, which can crack the plastic tabs that hold the fob together.
Removing and replacing the CR2032 battery
Once the fob is open, you will see the battery sitting in a plastic holder. It is a small silver disc about the size of a dime. Lift it straight up and out — it should come free with light pressure from your fingernail or a plastic spoon. Do not use a metal tool, which can scratch the battery or the holder.
Look at the side of the old battery facing up. It will have a plus sign (+) or minus sign (−) printed on it. The plus side is the positive terminal. Install your new CR2032 with the plus side facing the same direction. Drop it into the holder and press down gently until you hear or feel a small click. The battery should sit flat and flush with the plastic holder.
Closing the fob and testing the buttons
Align the two halves of the fob so the seams match up evenly. Press them together firmly until you hear a click. The fob should feel solid and not rattle. If it feels loose, the battery may not be seated correctly — open it again and check that the battery is sitting flat in its holder.
Press each button on the fob — lock, unlock, panic, trunk, or whatever buttons yours has. You should hear a beep from your car or see the lights flash. If nothing happens, the battery may be installed upside down. Open the fob again and flip the battery so the plus side faces the opposite direction, then test again.
Cleaning corroded contacts if the new battery does not work
If the fob still does not work after you install a fresh battery the correct way, the metal contacts inside the fob may be corroded. This happens when moisture gets inside the fob over time, especially if the fob is more than five or six years old or has been dropped in water.
Open the fob again and look at the metal contacts — small brass or copper circles on the plastic holder where the battery touches. If they look dark, green, or crusty, they need cleaning. Use a pencil eraser or a dry cloth to rub the contacts gently until they shine. Wipe away any eraser dust with a clean, dry cloth. Close the fob and test the buttons again.
If the contacts are heavily corroded or the fob still does not work, the circuit board inside may be damaged. At that point, replacing the entire fob is usually cheaper than trying to repair it. Acura dealerships sell replacement fobs, and aftermarket fobs from electronics retailers also work with most Acura models.
Where to buy CR2032 batteries
CR2032 batteries are stocked everywhere: drugstores like CVS and Walgreens, supermarkets, hardware stores, dollar stores, and online retailers. A single battery costs two to five dollars depending on the brand and where you buy it. Name brands like Duracell and Energizer cost more than store brands, but they last the same amount of time — usually three to four years in a key fob.
Buy a two-pack or four-pack if you have multiple key fobs or other devices that use CR2032 batteries. The price per battery drops when you buy in bulk, and the batteries last long enough in storage that buying extras makes sense. Keep one in your car's glove box so you have a spare if a fob dies while you are away from home.
Frequently Asked Questions
How often do I need to replace the battery in my Acura key fob?
Most CR2032 batteries last three to four years in a key fob, depending on how often you use the fob. If you press the buttons dozens of times a day, the battery may last only two years. If you use the fob sparingly, it may last five years or longer. You will know it is time to replace the battery when the buttons stop working or the car does not respond until you press the button multiple times.
Can I use a different battery size in my Acura key fob?
No. Acura key fobs are designed for CR2032 batteries specifically. Using a different size battery will not fit in the holder, and using a battery with a different voltage can damage the fob's circuit board. Stick with CR2032 replacements.
What should I do with the old battery?
CR2032 batteries contain lithium and should not be thrown in the trash. Take the old battery to a retailer that accepts battery recycling — most Best Buy locations, Home Depot stores, and battery retailers have collection bins. Some municipal hazardous waste facilities also accept batteries. Call your local waste management office to find a drop-off location near you.
Will replacing the battery erase my car's settings or my fob's programming?
No. Replacing the battery in your key fob does not erase any programming or settings. The fob will work exactly as it did before once the new battery is installed. Your car's memory of the fob is stored separately and is not affected by a battery change.
What if my key fob still does not work after I replace the battery and clean the contacts?
The fob's circuit board may be damaged, or the buttons themselves may be worn out. You can try opening the fob one more time and checking that the battery is installed correctly with the plus side facing up. If that does not work, you will need a replacement fob. Acura dealerships sell genuine fobs, and aftermarket fobs from electronics retailers are usually cheaper and work just as well.