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 itself does not need to be taken to a dealer — you open it with a flathead screwdriver or coin, swap the old battery for the new one, and snap it back together. The whole job takes longer to find the screwdriver than to do the work.

The steps are the same whether you drive a Subaru Outback, Crosstrek, Forester, or any other current model. Older Subarus (pre-2010) sometimes use different battery types, but the process is identical. If your fob is physically cracked or the buttons do not respond after you install a fresh battery, the fob itself may need replacement — but battery failure is the most common reason a fob stops working.

Key Takeaways

  • Subaru key fobs almost always use a CR2032 battery, which costs two to five dollars at any pharmacy or grocery store.
  • You need only a flathead screwdriver or a coin to open the fob; no special tools or dealer visit is required.
  • The battery slides out and in — note which side faces up before you remove the old one so you install the new one the same way.
  • If the fob still does not work after you install a new battery, the fob housing or buttons may be damaged and need replacement.

What battery your Subaru key fob uses

Nearly all current Subaru key fobs use a CR2032 lithium coin-cell battery. This is a round, flat battery about the size of a dime, and it is one of the most common battery types in the world. You will find CR2032 batteries at Target, Walmart, CVS, Walgreens, Amazon, and most hardware stores. A pack of two or four costs between two and five dollars.

If you own a Subaru older than 2010, check your owner's manual or the inside of your fob — some earlier models used CR2025 or CR2016 batteries instead. The process for replacing them is the same, but the battery type matters when you buy. If you are unsure, take a photo of the battery compartment or the old battery itself and show it to the cashier at any pharmacy.

How to open your key fob safely

Look at the seam running around the edge of your fob. You will see a small slot or groove on one side — this is where the two halves separate. Use a flathead screwdriver, a coin (a dime or penny works), or a plastic pry tool to gently wedge into that slot and twist slightly. You are not forcing it open; a small amount of pressure is enough.

The two halves will separate. Set the larger half (the one with the circuit board) face-down on a clean surface so you do not lose any small springs or contacts. The battery sits in a metal holder on the circuit board. Note which side of the battery faces up — the positive side (marked with a +) should face toward you when you look at the circuit board.

Removing the old battery and installing the new one

Slide the old battery out of its metal holder. If it is stuck, use your fingernail or a plastic tool to gently pry one edge up. Do not use a metal screwdriver on the battery itself — you want to avoid scratching the circuit board.

Take your new CR2032 battery and check that the positive side (marked +) faces the same direction as the old one did. Slide the new battery into the metal holder, positive side up. It should sit flat and snug. Do not force it — if it does not slide in easily, you may have the polarity reversed.

Closing the fob and testing it

Align the two halves of the fob so the seams match up. Press them together firmly until you hear or feel a click. The fob should be solid and not rattle when you shake it.

Stand near your Subaru and press any button on the fob — lock, unlock, or panic. You should see the lights flash on your car and hear the locks respond. If nothing happens, open the fob again and check that the battery is seated properly and facing the right direction. If the fob still does not work after a second attempt, the circuit board or buttons may be damaged.

When to replace the fob instead of just the battery

If you install a new battery and the fob still does not work, the problem is not the battery. Physical damage — a cracked case, water inside the fob, or worn-out button contacts — requires fob replacement rather than a battery swap. A new Subaru key fob costs between 150 and 300 dollars at a dealer, though some third-party fobs are cheaper.

You can also have a dealer replace the battery for you if you prefer not to do it yourself. Most dealers charge between 50 and 100 dollars for this service, which is why doing it at home saves money. If your fob is still under warranty or you are uncomfortable opening it, a dealer visit is a reasonable choice.

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 battery can damage the circuit board or cause the fob to malfunction. CR2032 is widely available — any pharmacy or grocery store should have it in stock or be able to order it the same day.

What if I lose a small spring or contact when I open the fob?

Take a photo of the inside of the fob before you open it, or open it over a white towel so small parts do not roll away. If you do lose a piece, a dealer can replace the entire fob. Do not try to reassemble it without all the parts — it will not work.

How long does a CR2032 battery last in a Subaru key fob?

Most CR2032 batteries last three to four years in a key fob, depending on how often you use it. If you use your fob multiple times a day, the battery may wear out sooner. Cold weather can also reduce battery life temporarily, though the battery usually works again once it warms up.

Do I need to reprogram my fob after I change 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.