You can replace a Subaru key fob battery yourself in under five minutes

Most Subaru key fobs use a CR2032 coin cell battery that you can buy at any drugstore or supermarket for two to five dollars. The fob opens with a flat tool — a coin, a flathead screwdriver, or even a butter knife — and the battery slides out without any soldering or special knowledge. The whole job takes longer to find the right battery than to install it.

The exact steps depend slightly on which Subaru model and fob generation you own, but the principle is the same across all of them: pry the case open, remove the old battery, drop in the new one with the positive side facing up, and snap the case shut. If your fob has stopped responding to button presses or only works from very close range, a dead battery is the most common cause.

Key Takeaways

  • Subaru key fobs almost always use CR2032 batteries, which cost two to five dollars at any pharmacy or grocery store.
  • You open the fob by inserting a flat tool into the seam between the two halves and twisting gently until the case separates.
  • The battery slides out of its holder; insert the new one with the flat positive side facing toward the circuit board.
  • The entire replacement takes under five minutes and requires no tools beyond what you already have at home.

What battery your Subaru key fob needs

The vast majority of Subaru key fobs from the last fifteen years use a CR2032 coin cell battery. This is a round, flat battery about the size of a dime, and it is one of the most common batteries made. You will find them in the pharmacy section, the electronics aisle, or the checkout counter of any drugstore, supermarket, or big-box retailer.

A pack of two or four CR2032 batteries costs between two and five dollars. Some fobs may use a CR2025 or CR2016 instead — these are slightly thinner versions of the same battery family — but CR2032 is by far the most common in Subaru fobs. If you are unsure which one your fob needs, open it first and look at the number printed on the battery itself, or check your owner's manual.

How to open your Subaru key fob

Look at the seam that runs around the edge of your fob where the two plastic halves meet. You will see a small slot or groove on one side — this is where you insert your flat tool. Use a coin, a flathead screwdriver, a butter knife, or even a plastic spoon. The tool does not need to be sharp; you are just using it as a lever.

Insert the flat edge into the slot and twist gently. You are not trying to force it; a small amount of pressure will cause the two halves to separate. Once you feel them start to give, you can usually finish opening the fob by hand. Be careful not to lose the small spring or contact pad that may fall out when you open it — these sit under the battery and need to go back in the same position.

Removing the old battery and installing the new one

Once the fob is open, you will see the battery sitting in a plastic holder. It is a round, silver disc. Gently pry it out with your fingernail or the edge of your flat tool — it should come free with very little force. If it is stuck, do not force it; a tiny bit of rocking back and forth will loosen it.

Before you install the new battery, check that the small metal contact pad or spring is still in place under where the battery sits. If it fell out, put it back now. Then slide the new CR2032 battery into the holder with the flat positive side facing up toward the circuit board. The battery will sit flat and snug in its holder. You should hear or feel a small click when it seats properly.

Closing the fob and testing it

Once the battery is in place, line up the two halves of the fob and press them together firmly until you hear a click. The seam should be flush all the way around. If there is a gap anywhere, the halves are not seated correctly — open it again and check that the battery and contact pad are in the right position, then try closing it once more.

Test the fob by pressing each button while standing near your Subaru. You should hear the locks click and see the lights flash. If nothing happens, open the fob again and make sure the battery is facing the right direction — the positive side must face toward the circuit board, not toward the plastic back of the fob. If the fob still does not work after you have checked the battery direction, the problem may be something other than the battery, and you may need to have the fob checked by a Subaru dealer.

What to do with the old battery

CR2032 batteries contain lithium and should not go in the regular trash. Most pharmacies and electronics retailers have a battery recycling bin near the checkout or customer service desk — you can drop the old battery there for free. Some communities also have hazardous waste collection days where you can bring batteries.

Check your local waste management website or call your city or county to find a drop-off location near you. Many retailers including Best Buy, Home Depot, and Lowe's also accept batteries for recycling at no charge. Taking a few seconds to recycle keeps lithium out of landfills and is the responsible choice.

Frequently Asked Questions

How do I know if my key fob battery is dead?

A dying battery usually shows up as reduced range — the fob only works when you are very close to the car — or buttons that require multiple presses to work. If the fob stops responding entirely, the battery is likely dead, though it could also be a broken button or circuit board. A new battery is the cheapest thing to try first.

Can I use a different battery type in my Subaru fob?

You should use the exact battery type specified in your owner's manual or printed on the old battery. Using a different size or chemistry can cause the fob to malfunction or damage the circuit board. CR2032, CR2025, and CR2016 are not interchangeable, even though they look similar.

What if my fob still does not work after I change the battery?

Check that the battery is facing the right direction — positive side up — and that the contact pad underneath is in place. If both are correct and the fob still does not work, the problem is likely a broken button, water damage, or a failed circuit board. Contact a Subaru dealer for repair or replacement.

How often do I need to replace the battery?

A CR2032 battery in a key fob typically lasts three to four years with normal use. If you use your fob frequently or leave it in a hot car, the battery may drain faster. You will notice the range shrinking before the battery dies completely, giving you time to pick up a replacement.