Open the key fob and remove the old battery
Most Subaru key fobs split open along a seam on the side or back. Look for a small slot or groove running around the edge—this is where the two halves separate. Insert a flathead screwdriver or a coin into the slot and gently twist to pry the fob apart. Do not force it; if it resists, try rotating the screwdriver slightly to find the exact seam.
Once the fob is open, you will see a small circular battery sitting in a plastic holder. Note which side faces up—the positive (+) side or negative (−) side. Take a photo with your phone if you are unsure. Gently pry the battery out using the screwdriver tip or your fingernail. Most Subaru fobs use a CR2032 battery, which is a common coin-cell type you can find at any drugstore, supermarket, or hardware store.
Key Takeaways
- Subaru key fobs typically use a CR2032 coin-cell battery that you can buy at any drugstore for a few dollars.
- Open the fob by finding the seam around the edge and gently prying it apart with a flathead screwdriver or coin.
- Note which side of the battery faces up before you remove it, so you install the new one the same way.
- Insert the new battery with the positive side facing up, close the fob, and test all buttons before putting it away.
Insert the new battery with the correct orientation
Before you install the new battery, check the inside of the fob for markings. Many fobs have a small (+) or (−) symbol printed on the plastic to show which side should face up. If you do not see markings, the positive side almost always faces up toward the button side of the fob.
Slide the new CR2032 battery into the holder with the positive side facing the direction you noted from the old battery. The battery should sit flat and snug in the plastic cradle. If it feels loose or tilted, remove it and try again—a poor connection is the most common reason a new battery does not work.
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 or feel a click. The fob should close flush with no gaps. If one side sits higher than the other, open it again and check that the battery is sitting flat in its holder.
Test each button on the fob—lock, unlock, panic, and trunk if your model has one. Press each button several times and listen for the click of the lock or watch for the lights on your Subaru to respond. If a button does not work, open the fob again and reseat the battery, making sure it is making full contact with both metal contacts inside the holder.
What to do if the fob still does not work after replacing the battery
If the new battery does not fix the problem, the battery may not be making good contact with the metal terminals inside the fob. Open the fob again and look at the two small metal contacts on the plastic holder. If they look dirty, corroded, or bent, gently clean them with a dry cloth or a pencil eraser. Reseat the battery and test again.
If the fob still does not respond, the problem may be inside the fob itself rather than the battery. The circuit board or buttons may be damaged, or the fob may have gotten wet at some point. At this stage, you will need to contact a Subaru dealer or a locksmith who can repair or replace the fob. Bring your vehicle identification number (VIN) with you; dealers use it to program a new fob to your car.
How to avoid damaging the fob while opening it
The plastic housing of a key fob is thin and can crack if you pry too hard. Start with a plastic pry tool or a coin rather than a metal screwdriver—plastic is less likely to slip and gouge the fob. If you do use a screwdriver, choose a small flathead and insert it gently into the seam. Twist slowly rather than jabbing or levering with force.
Work your way around the seam a little at a time instead of trying to open it all at once from one spot. This spreads the stress and reduces the risk of cracking a corner. If the fob has been dropped or sat in a pocket with keys, the seam may be slightly bent and harder to open—take extra time and patience rather than forcing it.
Where to buy a CR2032 battery and what to expect to pay
CR2032 batteries are sold at pharmacies, supermarkets, hardware stores, and online retailers. Common brands include Duracell, Energizer, Panasonic, and store brands. A single battery usually costs between two and five dollars, though buying a pack of two or four can lower the per-battery cost. Battery prices vary by location and retailer, so compare a few options if you are buying in person.
Online retailers often offer lower prices per battery if you buy in bulk, but you will need to wait for shipping. If your fob died unexpectedly and you need to get into your car right away, a pharmacy or supermarket is your fastest option. Keep a spare CR2032 battery in a drawer at home so you have one on hand the next time the fob dies.
Frequently Asked Questions
How long does a Subaru key fob battery last?
A CR2032 battery in a key fob typically lasts three to four years with normal use, though this varies based on how often you press the buttons. Fobs used daily may need a new battery sooner; fobs used occasionally may last longer. If your fob starts to work only when you press the button very hard, the battery is running low and should be replaced soon.
Can I use a different type of battery in my Subaru key fob?
No, stick with a CR2032 battery. Other coin-cell sizes like CR2025 or CR2016 may fit physically but will not provide the correct voltage, and your fob may not work or could be damaged. Always check your old battery or the fob's manual to confirm the type before buying a replacement.
What if I lose the two halves of the fob while it is open?
The plastic pieces are small and straightforward to misplace. Work over a table or a towel so parts do not roll away. If you do lose a piece, contact a Subaru dealer with your VIN—they can order a replacement fob housing or a complete new fob and program it to your vehicle.
Do I need to reprogram my key 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 reprogramming steps. If it does not work, the problem is likely a poor battery connection or a faulty fob, not a programming issue.