What you need before you start

A Subaru key fob battery dies like any other battery — usually between three and four years of regular use. You do not need a dealer visit or special tools. You need a small flathead screwdriver (a coin works), a replacement battery, and five minutes.

The battery type depends on your Subaru model year and fob design. Most Subaru key fobs from 2010 onward use a CR2032 battery, which costs $3 to $8 at any pharmacy, grocery store, or hardware store. A few older models use CR2025 or CR2016. Check your current fob or your owner's manual to confirm which one yours takes before you buy.

You do not need to remove the fob from your keychain or do anything to your car. This is a standalone task that takes place in your hand.

Key Takeaways

  • Most Subaru key fobs use a CR2032 battery, which you can buy at any pharmacy or grocery store for under $10.
  • The fob case splits in half along a seam on the edge — use a flathead screwdriver or coin to gently pry it open.
  • The battery sits in a small metal holder; note which side faces up before you remove it, then insert the new one the same way.
  • After you close the case, test the fob by pressing each button to confirm all functions work before you leave the store or house.

How to open the fob case

Look at the edge of your key fob. You will see a thin seam running around the perimeter where the two halves of the plastic case meet. This seam is where the fob splits open.

Insert the tip of a flathead screwdriver or the edge of a coin into the seam. Apply gentle, steady pressure — do not force it or twist hard. The case will separate slightly. Once you have a gap, work your way around the edge, lifting gently until the two halves come apart completely. The halves are held together by friction, not by clips or screws, so they come free easily once you start the separation.

Set one half aside on a clean surface. You are now looking at the circuit board and battery holder inside.

Remove and replace the battery

The battery sits in a small metal holder on the circuit board. It is a thin, round silver disc. Before you touch it, note which side is facing up — the positive side (marked with a +) or the negative side (marked with a −). This matters.

Use your fingernail or the screwdriver tip to gently pry the battery out of its holder. It will pop out easily. Discard the old battery or recycle it at a pharmacy or electronics store.

Take your new CR2032 battery and insert it into the holder with the same side facing up as the old one was. The battery will sit flat in the holder and stay in place on its own. Do not force it; it should rest there without pressure.

Close the fob and test it

Align the two halves of the fob case so the seam lines up evenly. Press them together firmly until you hear or feel a click. The case should close flush with no gaps. If there is a gap, the halves are not aligned correctly — separate them and try again.

Once the case is closed, test the fob immediately. Press the lock button, the unlock button, and any other buttons your fob has. You should hear the car respond or see the lights flash. If nothing happens, open the fob again and check that the battery is seated correctly in its holder and facing the right direction.

What to do if the fob still does not work

If you installed a new battery correctly and the fob still does not respond, the problem is not the battery. The circuit board may be damaged, or the fob may need reprogramming to your car.

Try this first: remove the battery again, wait 30 seconds, and reinsert it. Sometimes the circuit needs a reset. Close the case and test again.

If that does not work, contact a Subaru dealer or a local locksmith who programs car keys. They can test whether the fob itself is broken or whether it needs to be reprogrammed to your vehicle. This costs $50 to $150 depending on your location and model year, which is less than buying a new fob.

How often you need to replace the battery

A CR2032 battery in a Subaru key fob typically lasts three to four years with normal use. If you use your fob constantly — pressing the buttons many times per day — the battery may last only two to three years. If you use it rarely, it may last five years or longer.

You will know the battery is dying when the fob only works from very close to the car, or when you have to press the buttons multiple times before the car responds. At that point, replace the battery. Do not wait until the fob stops working entirely, because you may be locked out of your car.

Frequently Asked Questions

Can I use a different battery type if I cannot find a CR2032?

No. CR2032, CR2025, and CR2016 are different sizes and voltages. Using the wrong type can damage the circuit board or cause the fob to malfunction. Buy the correct battery for your model. If your store is out of stock, order it online or try another store rather than substituting.

What if I cannot get the fob case open?

You are likely pressing too hard or twisting instead of prying. Use a coin edge or plastic spoon instead of a metal screwdriver — metal can scratch the case. Insert the edge gently into the seam and apply steady, light pressure. Work your way around the entire edge before trying to separate the halves completely.

Do I need to reprogram the fob after changing the battery?

No. Changing the battery does not erase the fob's programming. Once you close the case and the battery makes contact, the fob should work immediately. If it does not, the programming may have been lost for another reason, and you will need to contact a dealer or locksmith.

Can I change the battery while the fob is still on my keychain?

Yes. The battery change does not affect your car or any other keys on the chain. You can leave the fob attached to your keychain the entire time. Just make sure you have a clean, flat surface to work on so you do not lose the small battery or the fob halves.