What you need to do before you start
Subaru key fobs use a coin-cell battery that typically lasts three to four years. When your key stops locking or unlocking the car from a distance, a dead battery is usually the cause. You can replace it yourself in about two minutes with a small flathead screwdriver and a replacement battery — you do not need to visit a dealer.
Before you begin, identify which Subaru key fob you have. Most modern Subaru fobs (2015 and newer) use the same battery type and opening method, but some older models differ slightly. Look at the back of your fob to see if there is a visible seam or slot where the two halves meet.
The most common battery type for Subaru key fobs is the CR2032, a coin-shaped lithium battery about the size of a dime. You can buy CR2032 batteries at any pharmacy, grocery store, hardware store, or online retailer for between $3 and $8 for a pack of several. Having a spare on hand is useful because key fob batteries fail without warning.
Key Takeaways
- Subaru key fobs typically use CR2032 coin-cell batteries that you can buy at any pharmacy or grocery store for a few dollars.
- The fob opens by inserting a flathead screwdriver into the slot on the back and gently twisting to separate the two halves.
- The battery sits in a small metal holder and slides out sideways — note which side faces up before you remove it so you can install the new one the same way.
- After inserting the new battery, press the two halves back together until they click, then test the lock and unlock buttons from a few feet away.
Opening the key fob safely
Look at the back of your fob. You will see a thin horizontal slot or seam running across the middle where the plastic halves meet. This is where you insert the screwdriver. Position a small flathead screwdriver (a jeweler's screwdriver works best, but any small flathead will do) into that slot.
Turn the screwdriver gently — do not force it. You are not trying to pry the fob apart; you are explore just enough rotational pressure to separate the two halves. Most fobs will pop apart with a quarter-turn or less. If it does not budge after a gentle twist, try inserting the screwdriver slightly deeper into the slot and try again.
Once the fob opens, you will see the battery sitting in a small metal holder in the center. The battery is round and flat, about the size of a dime. Do not touch the metal contacts on the battery itself — oils from your skin can reduce its performance.
Removing and replacing the battery
Before you take the old battery out, note which side is facing up. The side facing you will have either a + or − symbol printed on it. This matters because the battery must go back in the same direction — the positive side should face the same way it did before.
Slide the old battery out of its metal holder by pushing it gently to one side. It should slide out easily; if it does not, you may have a slightly different fob design, but gentle pressure will release it. Once it is out, set it aside.
Take your new CR2032 battery and slide it into the metal holder with the same side facing up as the old one. Push it in until it sits flat and snug in the holder. The battery should not move around or rattle when you gently shake the fob.
Closing the fob and testing the buttons
Align the two halves of the fob so the seam matches up evenly on all sides. Press them together firmly until you hear or feel a click. The fob should be solid and not flex or rattle when you squeeze it gently.
Stand a few feet away from your car and press the lock button on the fob. You should hear the car lock or see the lights flash. Press the unlock button and listen for the unlock sound or watch for the lights again. If both buttons work, the battery replacement is complete.
If the buttons do not work, open the fob again and check that the battery is sitting flat in its holder and facing the correct direction. Reclose it and test again. If it still does not work after a second attempt, the fob itself may have a different issue, and you should contact a Subaru dealer or a local locksmith.
When to replace the battery again
A new CR2032 battery typically lasts three to four years in normal use. You will notice the range of the fob getting shorter — you will have to stand closer to the car for the buttons to work — before the battery dies completely. When that happens, repeat these same steps with a fresh battery.
Keep a spare CR2032 battery in your glove box or at home so you are not stranded if your fob dies unexpectedly. Batteries are inexpensive and take only a couple of minutes to swap out, so having a backup is practical insurance.
What to do if your fob has a different design
Some older Subaru models (pre-2015) or certain specialty fobs may use a different battery type or opening method. If your fob does not have a visible seam on the back, it may have a small screw instead. Look for a tiny Phillips-head screw, usually near the bottom or side of the fob, and use a jeweler's Phillips screwdriver to remove it.
If you cannot locate a seam or screw, or if the fob design is unfamiliar, a Subaru dealer can tell you the correct battery type and opening method for your specific model. You can also call a local locksmith — most will have the information on hand and can sell you the correct battery if it is not the standard CR2032.
Frequently Asked Questions
Can I use a different battery type instead of CR2032?
No. CR2032 is the standard battery for most modern Subaru fobs, and using a different size or type will not fit the holder or may damage the fob. If your fob uses a different battery, the packaging or your owner's manual will specify which one. When in doubt, ask a Subaru dealer or locksmith.
What if I put the battery in backwards?
The fob will not work, but you will not damage anything. straightforward open it again, flip the battery so the correct side faces up, and close it. The positive (+) side should face the same direction it did in the old battery.
Do I need to reprogram the fob after changing the battery?
No. Changing the battery does not erase the fob's programming. Once you install the new battery and close the fob, it should work when ready without any additional steps.
How much does a replacement battery cost?
CR2032 batteries cost between $3 and $8 for a pack of several at most retailers. A Subaru dealer may charge $10 to $20 to replace the battery for you, but doing it yourself takes only a few minutes and costs far less.
What should I do with the old battery?
Lithium coin-cell batteries can be recycled. Many pharmacies and electronics retailers have battery recycling bins near the checkout. You can also check Earth911.com or call your local waste management office to find a recycling location near you.