Most Subaru key fobs use a CR2032 coin cell battery
The CR2032 is a 3-volt lithium coin battery about the size of a dime. It fits inside nearly all Subaru key fobs made in the last 15 years, regardless of model—Outback, Forester, Impreza, Legacy, Crosstrek, and others all use the same battery type. You can buy a CR2032 at any drugstore, grocery store, or hardware store for between $3 and $8, or in bulk packs of 4 to 10 for $10 to $15.
The battery typically lasts three to four years before the fob stops responding at normal distances. When the battery weakens, you may notice you have to stand closer to your car for the unlock button to work, or the button becomes less responsive. That is the signal to replace it.
Key Takeaways
- Subaru key fobs almost always take a CR2032 coin cell battery, a common 3-volt lithium type sold at any pharmacy or grocery store.
- The battery slides or pops out from a slot in the fob's edge or back, and you can replace it yourself in under one minute without tools.
- A CR2032 costs $3 to $8 per battery and lasts three to four years before needing replacement.
- If your fob still does not work after a fresh battery, the problem is likely a worn button contact or water damage inside the fob, not the battery itself.
How to open your Subaru key fob and access the battery
Look at the edge of your fob where the two plastic halves meet. Most Subaru fobs have a small slot or groove running along one edge. Insert a flat object—a coin, a butter knife, or a plastic pry tool—into that slot and gently twist to separate the two halves. Do not force it; the plastic is thin and cracks easily.
Some older Subaru fobs have a small button or latch on the back instead of a slot. Press or slide that button and the back cover pops off. Once the fob is open, you will see the battery sitting in a small metal holder or clip. The positive side (marked with a + symbol) faces up or toward you.
Slide the battery out of its holder with your fingernail or a plastic tool. Do not use a metal tool directly on the battery itself, as this can cause a short. Once the old battery is out, slide the new CR2032 in with the positive side facing the same direction as the old one was facing.
Reassembling the fob and testing it
Press the two halves of the fob back together until you hear or feel a click. The fob should snap shut without forcing. If it does not close smoothly, you may have inserted the battery upside down—open it again and flip the battery 180 degrees.
Test the fob by standing about 20 feet from your car and pressing the lock and unlock buttons. Both should work smoothly. If the fob still does not respond, open it again and make sure the battery is seated all the way in its holder and the positive side is facing the correct direction. A battery inserted backward will not power the fob.
Where to buy a CR2032 battery
CR2032 batteries are one of the most common battery types in the world and are stocked everywhere. Pharmacies like CVS and Walgreens, grocery stores, dollar stores, and hardware stores all carry them. You can also order them online from Amazon, eBay, or the websites of major retailers. Buying a pack of 4 or 10 is usually cheaper per battery than buying a single one, and the extras will work in other devices like watches, calculators, and car door locks.
Avoid extremely cheap batteries from unknown brands. A name-brand CR2032 from Energizer, Duracell, Panasonic, or Sony will last longer and is worth the small extra cost. The battery itself is so inexpensive that the difference between a $3 battery and a $5 battery is not worth the risk of a dead fob in a parking lot.
What to do if the fob still does not work after replacing the battery
If you have installed a fresh CR2032 and the fob still does not respond, the problem is not the battery. The most common cause is worn button contacts inside the fob. Over time, the rubber buttons wear down and no longer make solid contact with the circuit board underneath. This is not something you can fix at home without soldering equipment.
The second most common cause is water damage. If your fob has been dropped in water, rained on, or exposed to high humidity, moisture can corrode the circuit board or the battery contacts. You may see white or green corrosion inside the fob when you open it. In this case, you can try letting the fob dry completely in a warm, dry place for 24 to 48 hours, but corrosion damage is often permanent.
If the fob is damaged beyond a straightforward battery replacement, your Subaru dealer can reprogram a new fob to your car, or you can order a replacement fob online and have a locksmith or dealer program it. A new OEM (original equipment manufacturer) Subaru fob costs $150 to $300, while aftermarket fobs cost $30 to $80 and work just as well.
Extending the life of your key fob battery
Keep your fob away from extreme heat and direct sunlight. Leaving it on a hot dashboard or in a car during summer can shorten battery life. Also avoid dropping the fob or exposing it to water. If it gets wet, dry it when ready and let it sit in a warm place overnight before using it again.
Do not press the buttons unnecessarily. Every button press uses a tiny amount of battery power. If you use your fob dozens of times a day, the battery will drain faster than if you use it a few times. This is normal and not a sign of a problem—just replace the battery when it stops working at normal distances.
Frequently Asked Questions
Can I use a different battery type in my Subaru key fob?
No. The CR2032 is the only battery type that fits the fob's holder and provides the correct voltage. Using a different size or type will not work and may damage the fob. Stick with CR2032.
How do I know which side of the battery goes in first?
The positive side (marked with a +) should face the same direction as the old battery was facing. Usually this means the + side faces up or toward you when the fob is open. If you insert it backward, the fob will not work, but you can straightforward open it again and flip the battery.
Is it safe to replace the battery myself, or should I go to a dealer?
It is completely safe to replace the battery yourself. There is no programming involved and no risk of damaging the fob. A dealer will charge you $20 to $50 for the same five-second job. Save your money and do it at home.
What should I do with the old battery?
CR2032 batteries are safe to throw in the trash in most places, but some communities have battery recycling programs. Check your local waste management website to see if your area accepts batteries at a drop-off location. If not, regular trash is fine.
Why does my new battery only last a few months instead of three years?
A battery that drains quickly usually means the fob has a problem beyond the battery itself—either water damage, a stuck button, or a short circuit on the circuit board. If a new battery drains in weeks instead of years, the fob likely needs replacement rather than just a new battery.