How to Replace the Battery in Your Subaru Key Fob

You can replace a Subaru key fob battery yourself in about two minutes with a coin and a fresh battery

Subaru key fobs use a coin-cell battery, usually a CR2032 or CR2025 depending on your model year, that you can buy at any drugstore or supermarket for a few dollars. The fob itself is designed to open without tools — you slide a coin into the seam on the edge and gently pry the two halves apart. Once open, you lift out the old battery, drop in the new one with the positive side facing up, and snap the fob back together. The whole job takes longer to read about than to do.

The process is the same across all recent Subaru models, whether you drive a Crosstrek, Outback, Forester, or Legacy. The only variable is which battery type your fob uses, and you can determine that by looking at the old battery itself or checking your owner's manual.

Key Takeaways

Subaru key fobs split open along a seam on the edge using only a coin; no screwdriver or special tool is needed.
The battery type varies by model year — check your owner's manual or the old battery itself to confirm whether you need CR2032 or CR2025.
When you insert the new battery, the positive side (marked with a +) must face upward toward the circuit board.
If the fob still does not work after a new battery, the issue is likely a worn button contact or water damage inside the fob, not the battery itself.

Finding the seam and opening the fob

Look at the edge of your Subaru key fob — you will see a thin line running around the perimeter where the two plastic halves meet. This is the seam. Hold the fob in one hand with the buttons facing away from you, and use a coin (a dime or penny works fine) to gently pry at that seam. You are not forcing it; the fob is designed to separate easily. Start at one corner and work your way around if needed.

Once you feel it give, the two halves will come apart. Set the front half (the one with the buttons) aside carefully — the rubber button pad inside can fall out if you are not paying attention. The battery sits in a small metal holder on the back half of the fob. Take your time with this step; rushing can bend the metal clip that holds the battery in place.

Identifying and removing the old battery

The battery is a small, flat, coin-shaped disc sitting in a metal clip. Before you remove it, look at what is printed on its surface — you will see a model number like CR2032 or CR2025. Write this down or take a photo, because you need to buy the exact same type. The difference between these two is thickness, and using the wrong one can prevent the fob from closing properly or cause poor contact with the holder.

Gently lift the battery out of its holder. If it is stuck, use the edge of your coin to nudge it up. Do not force it; these batteries are not glued in. Once it is out, dispose of it properly — many retailers that sell batteries also take old ones for recycling at no charge.

Installing the new battery correctly

Before you put the new battery in, look at both sides. One side is marked with a + (positive) and the other is blank (negative). The positive side must face upward, toward the circuit board and the button pad. This is the most common mistake people make, and it is also the easiest to fix — if the fob does not work, open it again, flip the battery over, and try once more.

Place the new battery into the metal holder with the + side up. It should sit flat and find. You do not need to press hard; gravity and the clip will hold it in place. Double-check that the battery is not tilted or sitting at an angle before you close the fob.

Reassembling the fob and testing it

Before you snap the fob back together, make sure the rubber button pad is sitting properly on the front half. It should lie flat and not be twisted or bunched up. Line up the two halves so the seam is even all the way around, then press them together firmly until you hear or feel a click. The fob should close with a solid snap, not a loose or spongy feel.

Test the fob by pressing each button — lock, unlock, and panic if your model has one. You should see the LED light up inside the fob when you press a button, and your car should respond. If nothing happens, open the fob again and check that the battery is sitting flat with the + side up. If the LED lights but the car does not respond, the issue is likely a worn button contact or a problem with the car's receiver, not the battery.

What battery type your Subaru uses

Most Subaru key fobs from 2010 onward use a CR2032 battery, which is the most common coin-cell size. Some older models and certain trim levels use CR2025, which is slightly thinner. The safest way to know is to check your owner's manual — search for "key fob battery" or "remote battery" in the index. If you do not have the manual, you can also look at the old battery you just removed; the model number is printed right on it.

You can buy either type at a pharmacy, grocery store, dollar store, or online. A single battery costs between one and three dollars. Buying a pack of two or four is often cheaper per battery if you want spares on hand for future replacements.

When a new battery does not fix the problem

If you have installed a fresh battery with the correct polarity and the fob still does not work, the problem is not the battery. The most common culprit is worn rubber button contacts — the conductive material on the underside of the buttons wears down over time and stops making electrical contact. This cannot be fixed by replacing the battery; the button pad itself needs to be replaced, which usually means replacing the entire fob.

Water damage is another possibility, especially if the fob has been exposed to moisture or dropped in liquid. If you see corrosion inside the fob or the battery holder, or if the fob smells like rust, water damage is the issue. In this case, a new battery will not help, and you will need a replacement fob from a Subaru dealer or a third-party manufacturer.

Frequently Asked Questions

Can I use a different battery type if I cannot find the exact one?

No. CR2032 and CR2025 look almost identical but are different thicknesses. Using the wrong one can prevent the fob from closing properly or cause the battery to lose contact with the holder. Always use the exact type printed on your old battery or listed in your owner's manual.

How often do I need to replace the battery?

Most Subaru key fob batteries last between three and four years with normal use. If you use the fob heavily or live in a humid climate, it may need replacement sooner. There is no set schedule — you replace it when the buttons stop responding or the LED stops lighting up.

What if the fob still does not work after I replace the battery?

First, open the fob again and check that the battery is sitting flat with the + side facing up. If it is, the problem is likely worn button contacts or water damage inside the fob. You will need a replacement fob, which you can order from a Subaru dealer or purchase from a third-party manufacturer and have programmed by a dealer or locksmith.

Do I need to reprogram the fob after changing the battery?

No. Changing the battery does not erase the fob's programming. Once you install the new battery and close the fob, it should work when ready without any additional steps.

Where can I buy a replacement battery?

CR2032 and CR2025 batteries are sold at pharmacies, grocery stores, dollar stores, hardware stores, and online retailers. They are inexpensive — usually one to three dollars per battery — and you do not need any special ordering or shipping time.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.