The battery in a Subaru key fob typically lasts three to four years and costs $3 to $10 to replace
You can replace the battery yourself in about two minutes using a coin and a replacement battery you can buy at any drugstore or supermarket. The fob does not need to go to a dealer, and the process does not require any tools beyond what you already have. Most Subaru key fobs use a CR2032 battery, which is a flat, coin-shaped cell about the size of a dime.
The exact steps depend slightly on which Subaru model and year you own, but the basic approach is the same across nearly all current Subaru vehicles. If your key fob is not responding to button presses, the battery is the first thing to check — a dead battery is the most common reason a fob stops working.
Key Takeaways
- Most Subaru key fobs use a CR2032 battery, which you can buy at pharmacies, supermarkets, and hardware stores for $3 to $10.
- You open the fob by inserting a coin into the slot on the edge and twisting gently until the two halves separate.
- The battery sits in a small metal holder and lifts straight out; note which side faces up before you remove it.
- After inserting the new battery with the same side facing up, press the two halves back together until they click.
- If the fob still does not work after a new battery, the problem is likely the fob itself or the vehicle's receiver, not the battery.
Finding the right battery type for your Subaru key fob
The CR2032 is the standard battery for Subaru key fobs sold in North America. It is a lithium coin cell, round and flat, about 20 millimeters across. You will find it in the battery aisle at any pharmacy, grocery store, or big-box retailer. Brands like Duracell, Energizer, and store-brand versions all work the same way.
If you are unsure whether your fob uses a CR2032, check the owner's manual for your vehicle year and model — it will list the battery type. You can also open the fob and look at the battery itself; the type is printed on the metal case. Buying the wrong size is unlikely because CR2032 is by far the most common, but checking takes 30 seconds and saves a trip back to the store.
Opening the key fob without damaging the case
Look at the edge of your key fob for a small slot or seam running around the perimeter. This is where the two halves of the fob meet. Insert a coin — a dime, penny, or quarter works — into the slot and twist gently. You are not trying to pry it open; the coin straightforward turns the fob like a screw, and the two halves will separate after a quarter turn or so.
If the fob does not open easily, do not force it. Twisting too hard can crack the plastic. Try a different coin or explore a tiny bit of pressure downward as you twist. Once you feel it start to give, stop and pull the halves apart by hand. The battery compartment will be when ready visible on one of the two halves.
Removing and replacing the battery
The battery sits in a small metal holder or clip inside the fob. Before you touch it, note which side is facing up — the positive side (marked with a plus sign) or the negative side (marked with a minus sign or left blank). This matters because the battery will only work if it is installed the correct way.
Lift the battery straight out of its holder. If it is stuck, use your fingernail or a plastic tool to gently pry one edge up. Do not use a metal tool, as it can scratch the circuit board. Once the old battery is out, place the new CR2032 into the holder with the same side facing up as the old one. Press down gently until you hear or feel a small click — the battery should sit flat and snug.
Closing the fob and testing the buttons
Align the two halves of the fob so the seam is even all the way around. Insert your coin into the slot and twist in the opposite direction from when you opened it — usually clockwise. You will feel resistance as the two halves come together. Stop when you feel them seat fully; you should hear a small click or feel them lock into place. Do not over-tighten, as this can crack the plastic.
Test the fob by pressing each button — lock, unlock, and panic if your model has one. You should hear a beep from your vehicle or see the lights flash. If nothing happens, remove the fob and check that the battery is seated correctly and facing the right direction. If the fob still does not work after a second attempt, the problem is likely the fob's circuit board or your vehicle's receiver, not the battery.
What to do if the fob still does not work
A new battery fixes the problem about 90 percent of the time. If your fob is still dead, try these steps before assuming it needs replacement. First, make sure the battery is installed correctly — remove it, wait 10 seconds, and reinstall it facing the same direction. Second, check that the two halves of the fob are fully closed and the seam is tight all the way around; a loose fob can lose contact with the battery.
If those steps do not work, test the fob's buttons by pressing them while you hold it near your ear — you may hear a faint clicking sound even if the vehicle does not respond. If you hear clicking, the fob's transmitter is working but your vehicle's receiver may be the problem. If you hear nothing, the fob's circuit board is likely damaged and replacement is the next step. A Subaru dealer can order a new fob, or you can buy an aftermarket fob online and have a dealer program it to your vehicle.
Frequently Asked Questions
Can I use a different battery type if I cannot find a CR2032?
No. Using the wrong battery size can damage the fob or cause it to malfunction. CR2032 batteries are widely available and inexpensive, so buying the correct type is worth the small effort. If your local stores are out of stock, you can order one online and have it arrive within a day or two.
How often do I need to replace the battery?
Most Subaru key fob batteries last three to four years under normal use. If you use your fob frequently or live in a very cold climate, the battery may wear out sooner. Once you replace it the first time, you will have a sense of how long it lasts for your driving habits.
What if I drop the fob in water?
Subaru key fobs are water-resistant but not waterproof. If your fob gets wet, dry it thoroughly with a soft cloth and let it sit in a warm, dry place for 24 hours before using it. If it still does not work, open it and check that the battery and circuit board are dry. A new battery may help if water corroded the contacts, but water damage to the circuit board usually means replacement is necessary.
Do I need to reprogram the 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 additional steps.