Open the key fob case without damaging the plastic

Most Subaru key fobs split open along a seam running around the edge. Look for a thin slot or groove on the side of the fob — this is where the two plastic halves meet. Insert a flat tool (a coin, butter knife, or flathead screwdriver works) into that slot and gently twist to pry the case apart. Do not force it; if you meet resistance, try a different spot along the seam.

Once you have created a small gap, work your way around the edge, lifting gently as you go. The two halves should separate without cracking. If your fob has a metal key ring attached, you may need to remove it first by sliding the key out of its holder.

Identify and remove the old battery

Inside the fob you will see a small round battery sitting in a plastic holder. Most Subaru fobs use a CR2032 battery, which is a coin-cell battery about the size of a dime. Note which side is facing up — the positive side (marked with a + symbol) typically faces toward you when you look at the open fob.

Gently pry the old battery out of its holder using a plastic tool or the edge of a coin. Avoid touching the battery contacts with your bare fingers, as oils can reduce conductivity. If the battery is stuck, a small amount of gentle rocking side to side usually frees it.

Key Takeaways

  • Subaru key fobs typically use a CR2032 coin-cell battery, which you can find at any drugstore, grocery store, or hardware store for under five dollars.
  • Open the fob by inserting a flat tool into the seam around the edge and gently prying the two plastic halves apart.
  • Note the direction the old battery faced before removing it, so you can insert the new one the same way.
  • Push the new battery firmly into its holder until it clicks or sits flush, then snap the fob case closed and test all buttons before putting it away.

Insert the new battery in the correct direction

Purchase a replacement CR2032 battery from a pharmacy, grocery store, or hardware store. Before inserting it, confirm the positive side (marked +) faces the same direction as the old battery did. Slide the new battery into the holder and press down firmly until you hear or feel a click, or until it sits completely flat in the holder.

Do not force the battery; it should seat smoothly. If it does not sit flush, remove it and check that you have the correct orientation. A battery inserted backward will not power the fob, but it will not damage anything — you straightforward need to flip it and try again.

Close the fob case and test the buttons

Align the two plastic halves so the seam matches up evenly all the way around. Press down firmly along the edge until you hear a click or feel the case snap shut. Start at one end and work your way around to may support an even seal. The fob should feel solid when closed, with no gaps or loose edges.

Press each button on the fob — lock, unlock, and panic (if your model has one) — and listen for the clicking sound that indicates the fob is transmitting a signal. Walk toward your Subaru and test whether the doors lock and unlock. If the buttons do not respond, open the fob again and check that the battery is seated properly and facing the correct direction.

What to do if the fob still does not work

If the fob buttons click but your car does not respond, the problem may not be the battery. The fob may need to be reprogrammed to your vehicle, or the receiver in your car may have an issue. Consult your Subaru owner's manual for reprogramming steps, which usually involve turning the ignition on and off in a specific sequence while holding a button on the fob.

If the buttons do not click at all when pressed, remove the fob again and double-check that the battery is fully seated and facing the correct direction. A battery that is not quite flush will not make contact with the terminals. If you have confirmed the battery is correct and properly installed, the fob itself may be damaged and require replacement.

Where to buy a CR2032 battery

CR2032 batteries are sold at nearly every pharmacy and grocery store, usually in the health and beauty section near the hearing aid supplies or in the electronics aisle. Hardware stores, big-box retailers, and online marketplaces also stock them. A single battery typically costs between one and three dollars, and many stores sell multipacks for slightly less per battery if you want spares on hand.

When you buy a battery, check the expiration date on the package. Batteries do not expire in the traditional sense, but they lose charge slowly over time if stored. A battery manufactured within the past year or two will perform better than an older one sitting on a shelf.

Frequently Asked Questions

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

No. Subaru key fobs are designed for CR2032 batteries specifically. Other coin-cell batteries like CR2025 or CR2016 may fit physically but will not provide the correct voltage or may not fit the contacts properly. Always use CR2032.

How often do I need to replace the battery?

A CR2032 battery typically lasts three to four years in a key fob, depending on how often you use it. You will notice the buttons becoming less responsive or requiring harder presses before the battery dies completely. Replace it as soon as you notice this change.

What if I drop the battery or it gets wet?

A dropped battery is usually fine — coin cells are durable. If it got wet, dry it thoroughly with a soft cloth before inserting it. If water got inside the fob case itself, leave the fob open and let it air-dry for several hours before reassembling.

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

No. Changing the battery does not erase the fob's programming. It will work when ready once you close the case and the battery makes contact. Reprogramming is only necessary if the fob stops responding to your car even after you have confirmed the battery is fresh and properly installed.

Is it safe to touch the battery with my bare hands?

Yes, it is safe. Touching a CR2032 battery with your bare hands will not hurt you or the battery. However, oils from your skin can slightly reduce the conductivity at the contacts, so wiping the battery with a clean, dry cloth before inserting it is a good habit.