A Subaru key fob battery usually lasts three to four years and costs $3 to $8 to replace
You can replace a Subaru key fob battery yourself in about two minutes without any tools or a trip to the dealer. The battery type varies by model year and fob style, but the process is nearly identical across all Subaru vehicles. Most fobs use a CR2032 or CR2025 battery, both of which are common coin-cell batteries sold at drugstores, supermarkets, and hardware stores.
The first sign your battery is failing is that the buttons require harder pressing or only work from very close range. If the fob stops working entirely, the battery is dead. Before you assume it needs replacement, press each button several times—sometimes dirt or corrosion on the contacts makes it seem dead when it just needs cleaning.
Key Takeaways
- Subaru key fobs use CR2032 or CR2025 coin-cell batteries that cost $3 to $8 and are sold at most retailers.
- You can open most Subaru fobs by sliding a flat tool into the seam on the side or back and gently prying the two halves apart.
- Note which side of the battery faces outward before you remove it, because the new battery must go in the same way.
- If the fob still does not work after you install a fresh battery, the contacts may need cleaning with a pencil eraser or the fob may have internal damage requiring dealer service.
Identify your Subaru fob type and battery size
Subaru makes two main fob styles: a flat rectangular design and a more rounded design with a panic button. Both open the same way, but the battery compartment layout differs slightly. Check your owner's manual or search online for your model year and fob style to confirm whether you need a CR2032 or CR2025—the difference is thickness, and using the wrong size can prevent the fob from closing properly.
If you do not have the manual, you can also open the fob and look at the battery itself. The size is printed on the edge. Take a photo of it before you remove it so you know exactly what to buy. Most Subaru models from 2010 onward use CR2032, which is the more common size.
Open the fob without damaging the case
Look for a small seam running along the edge of the fob—usually on the side or the back. Slide a flat tool like a coin, flathead screwdriver, or plastic pry tool into the seam and explore gentle, steady pressure. Do not twist or force it; the two halves should separate with light pressure. If it resists, try a different spot along the seam.
Once the fob cracks open, you will see the battery sitting in a small plastic holder. The battery is usually held in place by a slight lip or groove, not glued. Gently lift one edge of the battery with your fingernail or the flat tool and slide it out. Be careful not to touch the metal contacts inside the fob, as skin oils can cause corrosion.
Install the new battery correctly
Before you insert the new battery, look at how the old one was oriented. The side marked with a + or a flat surface should face outward (toward you), and the unmarked or domed side should face the circuit board inside. This matters—a battery installed backward will not work.
Slide the new battery into the holder with the correct side facing out. It should fit snugly without forcing. Press gently until it sits flat in the groove. If it does not sit flush, remove it and check the orientation again. Once it is seated, close the fob by pressing the two halves together until you hear or feel a click.
Test the fob and troubleshoot if needed
Stand near your Subaru and press each button on the fob—lock, unlock, and panic if your model has one. You should see the lights flash and hear the doors lock or unlock. If the fob works when ready, you are done. If it does not work, open the fob again and check that the battery is seated correctly and facing the right direction.
If a fresh battery still does not work, the problem may be dirty contacts. Remove the battery and look at the metal contacts inside the fob—they should be shiny. If they look dark or corroded, gently rub them with a pencil eraser, wipe away any debris with a dry cloth, and try again. If the fob still does not respond, the internal circuit board may be damaged and the fob will need replacement from a Subaru dealer.
Where to buy replacement batteries
CR2032 and CR2025 batteries are sold at nearly every pharmacy, grocery store, and hardware store in the battery aisle. Walmart, Target, CVS, Walgreens, and Amazon all carry them. A single battery costs $3 to $8 depending on the brand. Name brands like Energizer and Duracell last longer than generic versions, but any reputable brand will work. Some stores sell multipacks if you want to keep spares on hand.
You can also buy batteries at Subaru dealerships, but they charge significantly more—often $10 to $15 per battery. Buying retail is faster and cheaper unless you are already at the dealer for service.
When to replace the entire fob instead
If your fob is physically cracked, the buttons are stuck or unresponsive even after cleaning, or the battery replacement does not restore function, the fob itself has failed. A replacement fob from a Subaru dealer costs $150 to $300 depending on the model and whether it includes programming. Some dealers will program a fob you buy elsewhere, though they may charge a programming fee of $50 to $100.
You can also buy aftermarket fobs online for $30 to $80, but you will need to have them programmed by a dealer or a locksmith. The programming step is not optional—a new fob will not work with your car until it is paired to your vehicle's receiver. Budget for that cost when deciding whether to repair or replace.
Frequently Asked Questions
How do I know if my key fob battery is dead or if something else is wrong?
A dead battery usually means the buttons require very hard pressing or only work from a few feet away. If the fob does not work at all, try a fresh battery first—it is the cheapest fix. If a new battery does not restore any function, the fob itself is likely damaged and needs replacement.
Can I use a different battery size if I cannot find the exact one?
No. CR2032 and CR2025 are different thicknesses, and using the wrong size can prevent the fob from closing or cause the battery to rattle inside. Always use the size printed on your old battery or listed in your owner's manual.
What if I accidentally installed the battery backward?
The fob straightforward will not work. Open it again, flip the battery so the + side faces outward, and close it. There is no damage from a backward battery—it just will not make contact with the circuit board.
Do I need to reprogram my Subaru after replacing the battery?
No. Replacing the battery in an existing fob does not require any programming. Programming is only needed when you add a brand-new fob to your car. A battery replacement is just a swap of the power source.
How long does a new key fob battery last?
Most Subaru owners get three to four years from a single battery before it needs replacement again. Heavy use—pressing the buttons many times daily—can shorten that to two years. Leaving the fob in extreme heat or cold can also reduce battery life.