You can replace a Subaru key fob battery yourself in about five minutes with a coin and a fresh battery
Most Subaru key fobs use a CR2032 coin-cell battery that you can buy at any drugstore, grocery store, or hardware store for two to five dollars. The fob itself is designed to open without tools—you just need a flat coin like a penny or dime. Once you have the battery, the whole job takes less time than it takes to drive to a dealership.
The steps are the same whether you have a newer Subaru or an older one, because Subaru has kept the key fob design consistent for years. If your fob is cracked or the buttons don't work even after you replace the battery, that is a different problem, but a dead battery is almost always the culprit when your fob stops responding.
Key Takeaways
- Subaru key fobs use a CR2032 battery, which costs two to five dollars and is sold at most stores that have a pharmacy or automotive section.
- You open the fob by inserting a flat coin into the slot on the edge and twisting gently—no screwdrivers or special tools needed.
- The battery sits in a metal holder with a plus sign facing up; note which way it sits before you remove it so you can install the new one the same way.
- After you close the fob, test all four buttons to make sure the new battery is making contact and the fob is working.
What battery your Subaru key fob needs
The battery is a CR2032, a round coin-shaped cell about the size of a dime but thicker. You will see this exact model number printed on the packaging at any pharmacy, supermarket, or auto parts store. Duracell, Energizer, and store brands all work equally well—the important thing is that it says CR2032 on the package.
A CR2032 costs between two and five dollars depending on where you buy it and whether you buy a single battery or a pack. If you buy a pack of two or four, you will have spares for future replacements or for other devices like watches or car door locks that also use CR2032 batteries.
How to open the key fob
Look at the edge of your key fob for a small slot or seam running along one side. This is where the two halves of the fob meet. Insert a flat coin—a penny, dime, or quarter works—into that slot and turn it gently, as if you were opening a battery compartment on a remote control. You are not forcing it; you are just explore steady pressure until the two halves separate.
The fob will split into a front half and a back half. Set the front half aside somewhere safe so you do not lose the rubber button pad inside. The battery sits in a metal holder in the back half, held in place by friction—it does not have a clip or screw.
Removing and replacing the old battery
Before you touch the old battery, look at which side is facing up. The side with a plus sign (+) should be facing toward you. This matters because you need to install the new battery the same way—plus side up. If you install it backwards, the fob will not work.
Gently pry the old battery out of its metal holder using your fingernail or the edge of the coin. It should come out easily without any force. Drop it aside—do not throw it in the trash; most pharmacies and electronics stores have battery recycling bins near the checkout.
Take your new CR2032 battery and check that the plus sign is on one side and the minus sign (or blank side) is on the other. Place the battery into the metal holder with the plus sign facing up, the same direction the old one was facing. Press down gently until you hear or feel a small click—the battery is now seated in the holder.
Closing the fob and testing it
Line up the front half of the fob with the back half so the rubber button pad sits inside the front piece. Press the two halves together firmly until you hear a click or feel them snap into place. The seam should be tight all the way around with no gaps.
Now test the fob by pressing each of the four buttons—lock, unlock, panic, and trunk (or whatever buttons your model has). You should hear a beep or see the lights on your Subaru respond to each button press. If nothing happens, open the fob again and check that the battery is seated all the way down in the metal holder and that the plus side is facing up.
What to do if the fob still does not work
If you installed a fresh battery correctly and the fob still does not respond, the problem is not the battery. The most common cause is that water got inside the fob and corroded the circuit board or the button contacts. If you have dropped the fob in water or spilled liquid on it, that is likely the issue.
Another possibility is that one of the rubber buttons has worn through or cracked, breaking the electrical contact. You can sometimes see this by looking at the rubber pad—if a button looks thin or damaged, that button will not work even with a new battery.
If the fob is damaged beyond a straightforward battery replacement, a Subaru dealership can program a new fob for you, though this costs more than the battery itself. Some independent locksmiths also program Subaru fobs and may charge less than the dealership.
How often you need to replace the battery
A CR2032 battery in a key fob usually lasts between three and four years with normal use. If you use your fob every day, you might need to replace it sooner. If you rarely use it, it might last longer. You will know it is time when the buttons stop responding or respond only when you press them very hard.
Some Subaru models have a low-battery indicator light on the fob itself, though this is not common on older models. If your fob has one and it lights up, that is a sign to replace the battery soon, even if the buttons still work.
Frequently Asked Questions
Can I use a different battery size if I cannot find a CR2032?
No. A CR2032 is the only battery that fits the metal holder in a Subaru key fob. Other sizes will not make contact or will fall out. CR2032 batteries are sold everywhere, so you should not have trouble finding one.
What happens if I install the battery backwards?
The fob will not work at all. The battery will not make electrical contact if the plus and minus sides are reversed. If you test the fob and nothing happens, open it again and flip the battery over so the plus sign faces up.
Do I need to reprogram the fob after I replace the battery?
No. Replacing the battery does not erase any programming. The fob will work exactly as it did before once you install the new battery and close the case.
Is it safe to replace the battery myself, or should I go to a dealership?
It is completely safe to replace it yourself. There is no risk of damage to the fob or your car. The battery compartment is not sealed, and there are no electrical hazards. A dealership will charge you thirty to fifty dollars for the same five-minute job.
Where should I buy the CR2032 battery?
Any pharmacy, supermarket, or auto parts store sells CR2032 batteries. Walmart, Target, CVS, Walgreens, and AutoZone all stock them. Online retailers like Amazon also sell them, but you will have to wait for shipping.