You can replace your Subaru key fob battery yourself in about five minutes
Most Subaru key fobs use a coin-cell battery—usually a CR2032 or CR2025—that you can buy at any drugstore, supermarket, or hardware store for two to five dollars. The battery typically lasts three to four years depending on how often you use the fob. When the buttons stop responding or respond slowly, a dead battery is almost always the cause. You do not need any tools except a coin or flathead screwdriver, and the whole job takes longer to read about than to do.
The steps are the same across most Subaru models from the last 15 years, though the exact fob shape varies. If your fob has a physical key blade inside, you will need to remove that first—it slides or twists out depending on the model year. Once the blade is out, you can open the fob case and swap the battery.
Key Takeaways
- Subaru key fobs use CR2032 or CR2025 coin-cell batteries that cost two to five dollars and last three to four years.
- You need only a coin or flathead screwdriver to open the fob; no special tools or dealer visit is required.
- The battery sits in a small metal holder inside the fob case, and you pry it out with the edge of a coin or screwdriver.
- The entire replacement takes about five minutes and works the same way on most Subaru models made in the last 15 years.
- If the fob still does not work after you replace the battery, the problem is likely a worn button contact or a broken circuit board, not the battery.
Locate the seam on your fob and pry it open
Hold your Subaru fob with the buttons facing you. Look for a thin seam running around the edge—usually horizontal, sometimes vertical depending on the model. This seam is where the two halves of the plastic case meet. Slide a coin (a dime or penny works well) or a flathead screwdriver into the seam and gently twist to create a gap. Do not force it; the case is designed to pop apart with light pressure.
Once you have a gap, work your way around the seam with the coin, lifting a little at each point until the two halves separate. You will see the circuit board and battery holder inside. The battery is a small silver disc sitting in a metal cradle. Do not touch the circuit board itself or the button contacts—oils from your skin can interfere with the electrical connection.
Remove the old battery and insert the new one
The battery sits in a metal holder with a small lip on one side. Use the edge of your coin or screwdriver to pry the battery up from the side without the lip. It will pop out easily once you explore gentle upward pressure. Set the old battery aside.
Before you insert the new battery, check the packaging to confirm it is the correct type for your fob—CR2032 is most common, but some older Subaru models use CR2025. The new battery should be the same size and thickness as the one you removed. Slide the new battery into the metal holder with the positive side (marked with a +) facing up. It should sit flat and click into place. If it does not sit flush, you have it upside down—flip it and try again.
Close the fob case and test the buttons
Align the two halves of the fob case so the seam lines up evenly. Press down firmly along the seam until you hear or feel a click. Start at one end and work your way around, pressing at several points to make sure both halves are seated. The fob should feel solid and not have any gaps or loose spots.
Test each button—lock, unlock, and panic if your model has one. The buttons should respond when ready and consistently. If they do not, remove the fob again and check that the battery is seated correctly and facing the right direction. If the battery is correct and the buttons still do not work, the problem is likely a worn button contact or internal damage, not the battery itself.
What to do if your fob has a removable key blade
Some Subaru fobs have a physical key blade stored inside the case. Before you open the fob, you need to remove this blade. Look for a small slot or button near the edge of the fob where the blade emerges. Press or slide this release, and the blade will pop out or slide free. Set it aside in a safe place—you will not need it for the battery replacement, but you will want to put it back when you are done.
Once the blade is out, proceed with opening the fob case as described above. When you have finished replacing the battery and closed the fob, reinsert the blade by sliding or clicking it back into its slot until it locks in place.
Common mistakes that prevent the battery from working
The most frequent error is installing the battery upside down. The positive side (marked with a +) must face up toward the buttons, not down toward the circuit board. If your buttons do not work after replacement, open the fob again and flip the battery. This fixes the problem in about 80 percent of cases where the new battery does not work when ready.
Another common mistake is not seating the battery fully in the metal holder. If the battery is tilted or sitting at an angle, it will not make proper contact with the electrical terminals. Push down gently on the battery after you insert it to make sure it is flat and clicks into place. You should not be able to wiggle it with your finger.
A third mistake is touching the circuit board or the metal contacts inside the fob. Skin oils can create a thin film that blocks electrical flow. If you accidentally touch these parts, wipe them gently with a clean, dry cloth before closing the fob.
When to replace the entire fob instead of just the battery
If you have replaced the battery and tested it twice, and the buttons still do not respond, the problem is not the battery. The most likely cause is worn button contacts—the rubber pads under the buttons wear thin over time and stop conducting electricity. You can sometimes fix this by cleaning the contacts with a pencil eraser, but if that does not work, you will need a replacement fob.
Subaru dealerships sell replacement fobs, and you can also find them from third-party sellers online. Prices range widely depending on whether you want an OEM (original equipment manufacturer) fob or an aftermarket one. You will need to have the new fob programmed to your vehicle, which a dealership can do—some aftermarket fobs come with programming instructions for DIY setup, though this varies by seller.
Frequently Asked Questions
How do I know which battery type my Subaru fob uses?
The easiest way is to remove the old battery and read the number stamped on it—CR2032 or CR2025 are the most common. If you cannot read the old battery, check your owner's manual or call your Subaru dealership with your vehicle's year and model. You can also take the old battery to a pharmacy or electronics store and ask them to match it.
Can I use a different battery type if I cannot find the exact one?
No. CR2032 and CR2025 look similar but have different thicknesses, and using the wrong one can prevent the battery from making proper contact. Always use the exact type that came out of your fob. Most stores carry both types, so finding the right one is not difficult.
What should I do with the old battery?
Coin-cell batteries contain lithium and should not go in the trash. Most pharmacies, electronics stores, and municipal hazardous waste facilities accept used batteries for recycling. Some stores that sell batteries also have a take-back program. Call ahead to confirm they accept coin-cell batteries before you visit.
Why is my fob not working even though I replaced the battery?
First, open the fob again and check that the battery is facing the right direction—positive side up. If it is, remove the battery and clean the metal contacts inside the fob with a dry cloth, then reinsert it. If the buttons still do not work, the problem is likely worn button contacts or a damaged circuit board, not the battery. You will need a replacement fob in this case.
Do I need to reprogram my fob after replacing the battery?
No. Replacing the battery does not erase the fob's programming. Once the new battery is in and working, the fob should function exactly as it did before. If it does not work after the battery replacement, the issue is not programming—it is a hardware problem inside the fob.