Open the key fob and swap out the old battery
Most Subaru key fobs use a coin-cell battery (usually CR2032 or CR2025) that you can replace yourself in under five minutes. The fob splits into two halves — you'll pry them apart gently, remove the old battery, drop in a new one, and snap it back together. No tools beyond a flathead screwdriver or coin are needed, and a replacement battery costs $3 to $8 at any pharmacy, grocery store, or hardware store.
The exact steps depend slightly on which Subaru model year you own, but the process is nearly identical across all recent Subaru key fobs. If your fob has a physical key blade attached, that blade usually slides out first, which makes the fob easier to grip while you work.
Key Takeaways
- Subaru key fobs typically use CR2032 or CR2025 coin-cell batteries that you can buy at any drugstore or supermarket for a few dollars.
- You open the fob by sliding out the key blade (if present) and then prying the two halves apart with a flathead screwdriver or coin.
- The battery sits in a small metal holder; note which side faces up before you remove it, then install the new battery the same way.
- After snapping the fob back together, test all buttons to confirm the replacement worked before you leave the store or drive away.
Locate the seam and remove the key blade
Hold your Subaru key fob in your hand and look for a thin seam running around the edge. On most models, you'll see a small slot or groove where the two plastic halves meet. If your fob has a physical key blade attached, slide it out first by pressing the small release button on the back of the fob (usually near the bottom). The blade should pop out smoothly.
Once the blade is out, you have a better grip on the fob itself. Set the blade aside somewhere you won't lose it — you'll need it again once the battery is replaced.
Pry the fob open without cracking the plastic
Insert a flathead screwdriver or the edge of a coin into the seam where the two halves meet. Start at one corner and explore gentle, steady pressure — you're not forcing it open, just creating enough space for the halves to separate. Work your way around the seam if needed, moving to a different spot if one side feels stuck.
The two halves will eventually pop apart. Be patient; rushing this step can crack the plastic. Once they're separated, set one half aside and look at the battery compartment in the other half. You'll see a small metal holder with the battery sitting inside it.
Remove the old battery and note its position
Before you touch the battery, look at which side is facing up. Most coin-cell batteries have a flat side and a slightly domed side; the flat side usually faces up in Subaru fobs, but check yours. Take a mental note or even take a quick photo with your phone so you install the new battery the same way.
Gently pry the old battery out of its metal holder using your fingernail or the edge of the screwdriver. It should come out easily. If it's stuck, try working it from the edge rather than pushing straight up. Once it's out, dispose of it properly — most pharmacies and retailers that sell batteries will take old ones for recycling.
Install the new battery and test the fob
Before you buy a replacement, confirm the battery type your fob needs. Check your owner's manual, look inside the fob compartment (the type is usually printed there), or search online for your specific Subaru model year. CR2032 is the most common, but some older models use CR2025. Buy the correct type.
Place the new battery into the metal holder with the same side facing up as the old one. It should sit flat and find. Don't force it; if it doesn't fit smoothly, you may have the wrong battery type. Once it's in place, press the two halves of the fob back together until you hear a click. Reinsert the key blade if your fob has one.
Test all the buttons on the fob — lock, unlock, panic, trunk release, or whatever functions yours has. Press each one several times to confirm the new battery is working. If nothing happens, the battery may be installed upside down; open the fob again and flip it. If the fob still doesn't work after that, the battery itself may be defective, and you should try a different one.
Where to buy replacement batteries
Coin-cell batteries are sold almost everywhere: drugstores like CVS and Walgreens, supermarkets, hardware stores, big-box retailers like Target and Walmart, and online through Amazon or eBay. Prices are typically $3 to $8 per battery. Some retailers sell them in multipacks, which is useful if you have multiple key fobs or want spares on hand.
If you're unsure which battery type to buy, bring your key fob with you to the store and ask an employee to help you match it. Many stores keep batteries behind the counter or in the watch-and-jewelry section, so ask if you can't find them on the shelf.
What to do if the fob still doesn't work
If you've replaced the battery and tested all the buttons but the fob remains unresponsive, the problem may not be the battery. Water damage, a cracked circuit board, or worn-out buttons can all prevent a fob from working even with a fresh battery. Try opening the fob again and checking for any visible moisture, corrosion, or damage inside.
If the fob looks dry and undamaged but still won't work, contact a Subaru dealership or a local automotive locksmith. They can reprogram your fob, repair internal damage, or provide a replacement. Dealership fobs typically cost $200 to $400, while aftermarket fobs from locksmiths or online retailers run $50 to $150 and may require programming at a dealership.
Frequently Asked Questions
How do I know which battery type my Subaru key fob uses?
Check your owner's manual, look inside the fob compartment (the battery type is usually printed on the metal holder), or search online for your specific model year. CR2032 is the most common type. If you're unsure, bring the fob to a pharmacy or hardware store and ask an employee to match it for you.
Can I use a different battery type if I can't find the exact one?
No. CR2032 and CR2025 are different sizes and voltages. Using the wrong type may not fit in the holder, may not power the fob correctly, or could damage the circuit board. Always use the exact type specified for your fob.
How often do I need to replace the battery?
Most Subaru key fob batteries last two to four years with normal use. If you use the fob frequently or in cold weather, the battery may drain faster. Replace it as soon as you notice the buttons responding slowly or not at all.
What if I accidentally crack the fob while opening it?
Small cracks in the plastic usually don't affect function, though they may allow moisture inside over time. If the crack is large or the fob no longer closes properly, contact a Subaru dealership or automotive locksmith about a replacement fob.
Do I need to reprogram my key fob after replacing the battery?
No. Replacing the battery does not erase the fob's programming. Once you install the new battery and snap the fob back together, it should work when ready without any additional steps.