If you're standing in your driveway and clicking your remote with zero response, you probably need to know how to change battery in subaru fob right now so you can actually get where you're going. It's one of those minor annoyances that always seems to happen at the worst possible time—usually when you're running late or it's pouring rain. The good news is that you don't need to drive to the dealership and hand over forty or fifty bucks for something that takes about three minutes of your time and costs less than a cup of coffee.
Most Subaru owners eventually see that little "Key Battery Low" warning pop up on the dashboard, or they notice they have to stand closer and closer to the car just to get the doors to unlock. If that's you, don't sweat it. You don't need a degree in mechanical engineering to fix this. All you really need is a tiny bit of patience, a steady hand, and the right replacement coin cell.
What You'll Need Before You Start
Before you start prying things apart, let's make sure you have the right gear. There's nothing worse than opening up the fob only to realize you bought the wrong battery.
For the vast majority of modern Subaru fobs (the ones with the silver side trim or the newer rectangular push-button start styles), you're going to need a CR2032 battery. These are super common—you can find them at any grocery store, pharmacy, or hardware store. If you have an older Subaru with the teardrop-shaped remote or the integrated key, you might actually need a CR1632.
My best advice? Pop the fob open first, look at the number engraved on the old battery, and then go buy the replacement. It saves you a return trip to the store.
As for tools, a small flathead screwdriver is usually the MVP here. If you want to be extra careful not to scratch the plastic casing, you can wrap the tip of the screwdriver in a thin piece of tape or a microfiber cloth. Some people even just use the physical emergency key that's tucked inside the fob itself.
Opening the Modern Subaru Fob
Let's talk about the newer fobs first—the ones used for the Forester, Outback, Crosstrek, and Ascent from the last few years. These are actually designed pretty well for DIY battery swaps.
- Release the physical key: On the back of your fob, there's a tiny silver or black square button. Press and hold that down, then pull on the key ring. The metal emergency key should slide right out.
- Find the "sweet spot": Once the key is out, look into the slot where it used to be. You'll see a small little notch or a gap between the two halves of the plastic housing.
- Twist, don't pry: Insert your flathead screwdriver (or the tip of that emergency key you just pulled out) into that notch. Instead of trying to jemmy it open like a crowbar, give the tool a gentle twist. You'll hear a satisfying pop as the two halves of the shell start to separate.
- Work your way around: Carefully follow the seam around the edge of the fob with your fingers or the tool until the back cover comes off completely.
Inside, you'll see a circular green circuit board and, right in the center, the battery.
Swapping the Battery
Now that you're inside, the hard part is over. But there are a couple of things to watch out for so you don't accidentally damage the electronics.
When you go to take the old battery out, you might notice it's held in place by some tiny metal tabs. Don't just yank it. Use your fingernail or that small screwdriver to gently nudge it out from under the tabs.
Pro-tip: Before you put the new battery in, take a look at which way the "plus" (+) sign is facing. Usually, the positive side faces up toward you. If you put it in upside down, the fob won't work, and you'll be scratching your head wondering what went wrong.
Another little trick is to try and avoid touching the flat surfaces of the new battery with your bare fingers. The oils from your skin can actually create a bit of resistance and shorten the life of the battery. If you can, hold it by the edges or use a clean cloth. Slide the new battery in under those little metal clips until it clicks into place.
Putting It All Back Together
Reassembling the fob is much easier than taking it apart. Just line up the back cover with the front housing. Make sure everything is centered—if the circuit board shifted a bit, just nudge it back into its little plastic cradle.
Press the two halves together firmly. You should hear a series of clicks as the plastic tabs lock back into place. Once the seam is tight all the way around, slide your metal emergency key back into its slot until it clicks.
Give the buttons a press. On most Subarus, you'll see a tiny red LED light blink on the fob when you hit a button. If you see that light, you're golden. You successfully learned how to change battery in subaru fob without a trip to the service center.
Dealing with Older Subaru Remotes
If your Subaru is a bit older—maybe from the early 2010s or late 2000s—your fob might look a bit different. Some of these have a tiny screw on the back that you need to remove first. If yours has that, don't lose it! It's incredibly easy to drop that screw and have it vanish into the carpet forever.
Once the screw is out (or if your older fob just snaps together), the process is largely the same. Just be extra careful with the rubber membrane that sits over the buttons. Sometimes those get sticky or out of alignment over time. If it falls out, just set it back into the plastic front housing before you put the circuit board and battery back in.
What If It Still Doesn't Work?
So, you swapped the battery, the little light is blinking, but the car still isn't responding? Don't panic.
First, double-check that you actually put the battery in the right way. It sounds silly, but it happens to the best of us. If the polarity is wrong, nothing is going to happen.
Second, if your car has a push-button start and the battery was completely dead, the car might have "forgotten" the fob for a second. Try getting in the car and physically touching the Subaru logo on the key fob to the Start/Stop button while you press it. This uses a different type of signal (RFID) that doesn't actually require battery power to work. Often, once the car starts this way, it "re-syncs" with the fob, and you'll be back in business.
If you've done all that and it still won't unlock the doors, there's a small chance the fob itself has bit the dust or needs to be reprogrammed. But 99% of the time, a fresh CR2032 or CR1632 solves the problem immediately.
Why Do These Batteries Die So Fast?
It feels like we're changing these batteries every year or two, doesn't it? Well, modern Subaru fobs are actually "talking" to your car constantly. If you have the keyless entry system where the doors unlock just by you touching the handle, the fob is always sending out a "ping" to see if the car is nearby.
If you store your keys really close to where your car is parked—like on a hook right inside the garage door—the fob and the car might be "talking" all night long. This drains the battery way faster than if you kept the keys in a different room.
Anyway, it's a small price to pay for the convenience of never having to dig your keys out of your pocket. Now that you know how to change battery in subaru fob, you can just keep a spare battery in your junk drawer and never worry about being stranded again. It's a quick, easy DIY win that saves you time and money. Safe driving!