You can replace a Subaru key fob battery yourself in about five minutes with a coin
Most Subaru key fobs use a CR2032 coin-cell battery that you can swap out without tools or a trip to the dealer. The fob splits open along a seam, the old battery slides out, and a new one slides in. The whole job takes longer to find the battery than to install it.
You will need a CR2032 battery (about $3 to $8 at any drugstore, supermarket, or hardware store) and a coin—a penny, dime, or quarter works. That is it. No screwdrivers, no special equipment.
Key Takeaways
- Subaru key fobs almost always use CR2032 batteries, which you can buy at any pharmacy or grocery store for a few dollars.
- The fob opens by inserting a coin into the slot on the edge and twisting gently—you do not need to pry or force it.
- The battery sits in a small metal holder and slides out horizontally; note which side faces up before you remove it.
- A new battery should restore full range and button response within seconds of installation.
- If the fob still does not work after a fresh battery, the problem is likely the circuit board or buttons, not the power source.
Locate the seam and open the fob with a coin
Hold the key fob in your hand with the buttons facing you. Look at the edge of the fob—you will see a thin slot or seam running around the perimeter. This is where the two halves of the plastic case meet. The slot is usually on the side or bottom edge, depending on your fob model.
Insert a coin (penny, dime, or quarter) into the slot. Turn the coin gently, as if you were opening a battery compartment on a toy or remote control. You are not trying to pry the fob apart—just explore steady rotational pressure. The two halves will separate. If it does not budge after a few gentle turns, try a different spot along the seam; some fobs have the slot on the bottom rather than the side.
Once the fob cracks open, you can usually pull the two halves apart by hand. Be gentle—the plastic is not fragile, but the internal circuit board and button contacts are delicate. Set one half aside on a clean surface.
Remove the old battery and note its position
Inside the fob you will see a small metal battery holder with a circular battery sitting in it. The battery is a flat, coin-shaped disc—that is the CR2032. Before you touch it, look at which side is facing up. The side facing you will have either a + (positive) or − (negative) symbol printed on it. Write this down or take a photo with your phone.
Slide the battery out of the metal holder. It should come out easily; if it is stuck, gently rock it side to side rather than pulling straight up. Once it is out, set it aside. Do not throw it away yet—you may need to check it if the new battery does not work.
Install the new CR2032 battery with the correct side facing up
Take your new CR2032 battery out of the package. Look at the top side—it will have a + or − symbol. Orient the battery so the same symbol that was facing up on the old battery is facing up on the new one. This matters: if you install it backwards, the fob will not work.
Slide the new battery into the metal holder. It should fit snugly and sit flat. You will hear or feel a small click as it seats. Do not force it—if it does not slide in smoothly, you may have it upside down. Remove it, flip it, and try again.
Close the fob and test the buttons
Align the two halves of the fob so the seam lines up evenly. Press them together firmly until you hear a click or feel them snap into place. The fob should be solid and not rattle.
Press each button on the fob—lock, unlock, panic, trunk, or whatever buttons your model has. You should feel a firm click under each button and hear a beep from your car (if you are in range). If the buttons feel mushy or do not respond, the battery may be installed backwards. Open the fob again and flip the battery.
Walk toward your car and press the lock button from 20 to 30 feet away. The car should respond. If it does not, try from closer range. A new battery should restore full range when ready.
What to do if a new battery does not fix the problem
If you installed a fresh CR2032 battery with the correct polarity and the fob still does not work, the problem is not the battery. The issue is likely a worn button contact, a cracked circuit board, or corrosion inside the fob. These problems require a replacement fob, not a new battery.
You can buy an aftermarket Subaru key fob online for $20 to $60 and program it yourself using your car's ignition—most Subaru models let you program a new fob without going to the dealer. Subaru dealerships also sell OEM fobs and can program them for you, though that route costs more. If you choose to replace the fob, keep the old one; even a non-working fob can sometimes be repaired or recycled.
Where to buy CR2032 batteries and what to expect
CR2032 batteries are sold everywhere: drugstores (CVS, Walgreens), supermarkets (grocery store pharmacy sections), hardware stores (Home Depot, Lowe's), and online (Amazon, eBay). A single battery costs $3 to $8. A pack of two or four costs $5 to $12 and is usually better value if you have multiple fobs or devices.
Brand does not matter much for this process. Duracell, Energizer, Panasonic, and store brands all work the same way in a key fob. The battery should last two to four years depending on how often you use the fob. When it starts to die, the buttons will feel sluggish or the range will drop before the fob stops working entirely.
Frequently Asked Questions
Can I use a different battery size if I cannot find a CR2032?
No. The CR2032 is the only battery that fits the holder in a Subaru key fob. Other sizes will not make contact with the terminals. If you cannot find a CR2032 locally, order one online—they ship fast and cost just a few dollars.
What if I installed the battery backwards and now the fob is broken?
It is not broken. Open the fob again and flip the battery so the opposite side faces up. A backwards battery straightforward will not power the fob; it does not damage anything. Once you flip it, the fob should work when ready.
How do I know if my key fob uses a CR2032 or a different battery?
Open the fob and look at the battery. The size and model number are printed on the battery itself. Almost all Subaru key fobs use CR2032, but if yours is different, the battery will tell you what to buy. Take a photo of the old battery before you go to the store.
Do I need to reprogram the fob after changing the battery?
No. Changing the battery does not erase the fob's programming. As soon as the new battery is installed, the fob will work without any additional steps.
Why did my key fob battery die so quickly?
If a battery dies in less than a year, the fob may have a button stuck in the pressed position, draining power constantly. Open the fob and check that all buttons move freely and click back into place. If a button is stuck, the fob may need replacement rather than just a new battery.