What you need to know before you start

Most Subaru key fobs use a coin-cell battery — usually a CR2032 or CR2025 — that you can replace yourself in under five minutes without tools or a trip to the dealer. The battery typically lasts three to four years depending on how often you use the fob. You'll know it's time when the fob stops locking or unlocking from your normal distance, or when you have to press the buttons harder than usual.

The exact battery type and how the fob opens varies slightly by model year and generation. Subaru fobs from the 2000s onward generally follow the same process, but checking your owner's manual or the battery compartment itself before you buy a replacement battery will save you a trip back to the store.

Key Takeaways

  • Subaru key fobs almost always use a CR2032 or CR2025 coin-cell battery that you can buy at any pharmacy, grocery store, or hardware store for $3 to $8.
  • The fob typically opens by sliding a small metal or plastic tab on the edge, or by gently prying the two halves apart with a flat object like a coin or butter knife.
  • When you open the fob, note which side of the battery faces outward before you remove it, so you install the new one the same way.
  • After you insert the new battery, press each button on the fob several times to confirm it works before you close it back up.
  • If the fob still doesn't work after replacing the battery, the problem may be a worn button contact or internal damage rather than the battery itself.

Finding the right battery type for your Subaru

Before you open the fob, you need to know which battery it takes. The easiest way is to look at the battery compartment itself — most Subaru fobs have the battery type printed inside the case. Open your owner's manual and search for "key fob battery" or "remote battery," and you'll usually find the part number listed there as well.

If you can't find the manual or the printing is worn away, CR2032 is the most common battery for Subaru fobs made in the last 20 years. CR2025 is less common but still used in some models. Both are widely available at pharmacies, supermarkets, dollar stores, and online retailers. Buy a fresh battery rather than one that's been sitting in a drawer — coin cells lose charge over time even when unused.

Opening the key fob safely

Subaru key fobs open in one of two ways. The first and most common is a small metal or plastic slider on the edge of the fob. Look along the seam between the two halves of the fob for a thin tab or notch. Push or slide this tab in the direction the arrow points (if there is one), and the two halves should separate slightly. Once you see a gap, you can gently pry the halves apart with your fingernail or a flat object like a coin.

The second method, used on some older or newer Subaru models, is a seam you pry open directly. Hold the fob with the buttons facing away from you and look for a thin line running around the edge. Insert a flat object — a coin, butter knife, or plastic pry tool — into the seam and gently twist to pop the two halves apart. Work your way around the edge rather than forcing it in one spot, which can crack the plastic.

Once the fob is open, you'll see the battery sitting in a small compartment, usually held in place by a metal clip or spring. The battery has a flat side and a rounded side. Note which side faces outward before you remove it — this matters when you put the new one in.

Removing the old battery and installing the new one

If the battery is held by a metal clip, gently lift or slide the clip away from the battery to free it. If it's held by a spring, the spring will push the battery out slightly as you release the clip. Lift the old battery out carefully and set it aside.

Before you insert the new battery, check that it's the correct type and that it's clean. Wipe it with a dry cloth if it's dusty. Insert the new battery into the compartment with the same side facing outward as the old one was — usually the flat side faces down toward the circuit board, and the rounded side faces up. Press it gently until it sits flat and the clip or spring holds it in place.

Close the fob by pressing the two halves together until you hear or feel a click. If there's a slider tab, push it back to its original position. The fob should snap shut firmly without gaps.

Testing the fob before you finish

Before you put the fob away, test each button — lock, unlock, and panic if your model has one — while standing near your Subaru. Press each button several times and watch for the lights on your car to respond. If the fob works, you're done. If it doesn't, open the fob again and check that the battery is seated properly and facing the right direction.

If the fob still doesn't work after you've confirmed the battery is correct and properly installed, the problem is likely worn button contacts inside the fob or damage to the circuit board. In that case, you'll need a replacement fob from a Subaru dealer or a third-party supplier, though you can often find used fobs online that are cheaper than new ones.

Where to buy a replacement battery

Coin-cell batteries are sold almost everywhere. Pharmacies like CVS and Walgreens, grocery stores, hardware stores like Home Depot and Lowe's, and dollar stores all stock CR2032 and CR2025 batteries. Online retailers like Amazon also sell them, often in multipacks if you want spares. Prices range from $3 to $8 per battery depending on the brand and where you buy. Buying a multipack is usually cheaper per battery if you have multiple fobs or want backups.

Avoid very cheap batteries from unknown brands, especially if they've been in storage for a long time. A battery that's been sitting on a shelf for years may have lost charge and won't last as long as a fresh one. Check the packaging for a manufacture date if possible.

Frequently Asked Questions

Can I replace the battery myself or do I need to go to a Subaru dealer?

You can replace it yourself — it takes about five minutes and requires no special tools. Subaru dealers will replace it for you for a small fee, usually $10 to $20 plus the cost of the battery, but there's no reason to pay for that service unless you're uncomfortable opening the fob yourself.

What if I put the battery in backwards?

The fob won't work, but you won't damage anything. Simply open it again, flip the battery over, and close it back up. The battery has a flat side and a rounded side — the flat side typically faces down toward the circuit board.

How long does a new battery last?

Most coin-cell batteries in key fobs last three to four years with normal use. Heavy users who press the buttons many times a day may need to replace the battery sooner. The battery will gradually weaken over time, so you'll notice the fob working from a shorter distance before it stops working entirely.

Is there anything inside the fob I shouldn't touch?

Avoid touching the circuit board or the metal contacts inside the fob. If you do touch them, make sure your hands are dry. Don't use water or cleaning solutions inside the fob — if moisture gets into the electronics, it can cause permanent damage.

What should I do with the old battery?

Coin-cell batteries contain small amounts of lithium and should not go in the regular trash. Most pharmacies and retailers that sell batteries will take old batteries back for recycling at no charge. You can also check Earth911.com or Call2Recycle.org to find a recycling location near you.