You can replace a Subaru key fob battery yourself in under five minutes

Most Subaru key fobs use a coin-cell battery — typically a CR2032 or CR2025 — that you can buy at any pharmacy, grocery store, or hardware store for two to five dollars. The fob itself does not need to be taken apart with tools; it opens by hand or with a flat object like a coin. Once you swap the old battery for the new one, the fob works when ready. No programming or dealer visit is required.

The entire job takes longer to read about than to do. If your fob stopped responding, a dead battery is the most common cause, and this fix solves it in most cases.

Key Takeaways

  • Subaru key fobs use CR2032 or CR2025 coin-cell batteries that cost two to five dollars and are sold at drugstores and supermarkets.
  • The fob case opens by hand or with a coin inserted into the slot on the edge — no screwdriver or special tool is needed.
  • Remove the old battery, note which side faces up, and insert the new battery the same way, then snap the case closed.
  • The fob does not need to be reprogrammed after a battery change; it works when ready once reassembled.

What battery your Subaru key fob needs

Subaru key fobs from roughly 2010 onward use a CR2032 coin-cell battery. Some older models use a CR2025, which is slightly thinner but the same diameter. Both are 3-volt lithium batteries sold in the pharmacy or electronics section of most stores. A pack of two or four costs between two and five dollars.

If you are unsure which type your fob uses, open the case first — the battery itself is labeled with the model number. You can also check your owner's manual, which usually lists the battery type on the key fob page. When you buy the replacement, buy two; keeping a spare in your car or bag means you will not be stranded if the new battery dies sooner than expected.

How to open the key fob case

Look at the edge of your fob for a small slot or seam running along one side. Insert a coin — a dime or penny works — into that slot and twist gently. The case will separate into two halves. If the slot is not obvious, run your fingernail along all edges; Subaru fobs are designed to open by hand, and the seam is usually visible once you know where to look.

If you cannot locate a slot, your fob may open differently. Some Subaru models have a button on the back that you press to eject the battery cartridge. Check your owner's manual for your specific year and model if the coin method does not work.

Removing and replacing the battery

Once the case is open, you will see the battery sitting in a small metal holder. Note which side is facing up — the positive side (marked with a plus sign) should face toward you or toward the circuit board, depending on your fob design. Gently pry the old battery out with your fingernail or the edge of the coin.

Insert the new battery into the same holder, making sure the positive side faces the same direction as the old one did. The battery should sit flat and click into place. If it does not sit flush, you have it upside down — flip it and try again. Once it is seated, snap the two halves of the case back together until you hear a click.

Testing the fob after battery replacement

Stand near your Subaru and press any button on the fob — lock, unlock, or panic. The car should respond when ready. If the fob still does not work, the battery may be defective, or the problem may not have been the battery at all. Try a different new battery first; occasionally a battery from the store is dead on arrival.

If a second new battery does not work, the fob itself may have internal damage or a broken button contact. In that case, a replacement fob from a Subaru dealer or a third-party supplier is the next step. Dealer fobs usually cost between 200 and 400 dollars and may require programming; aftermarket fobs are cheaper but vary in quality.

Why your fob might still not work after a battery change

A dead battery is the most common reason a fob stops responding, but not the only one. If the buttons feel stuck or mushy, the contact pads inside may be worn out. If water got inside the case, corrosion on the circuit board can prevent the battery from making contact. If the fob was dropped or sat on, the internal components may be cracked.

You can sometimes clean corrosion by opening the fob again and gently wiping the battery holder and circuit board with a dry cotton swab. Let it air-dry for an hour before reassembling. If that does not help, or if the fob was physically damaged, replacement is usually the only option.

Where to buy a replacement battery

CR2032 and CR2025 batteries are stocked at pharmacies (CVS, Walgreens), supermarkets (most grocery stores have them in the pharmacy or electronics aisle), hardware stores (Home Depot, Lowe's), and online retailers. Buying in person means you can test the battery when ready; buying online is cheaper per battery if you buy in bulk, but you have to wait for shipping.

Avoid dollar stores and very cheap bulk packs; the batteries are often old stock with reduced charge. Stick with name brands like Energizer, Duracell, or Panasonic, or store brands from major retailers. A battery that costs fifty cents instead of two dollars is usually a sign it has been sitting on a shelf for years.

Frequently Asked Questions

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

No. A battery change does not erase the fob's programming. Once you insert the new battery and close the case, the fob should work when ready. Reprogramming is only needed if you buy a new fob or if the fob was already programmed to a different car.

How long does a key fob battery usually last?

A CR2032 or CR2025 battery typically lasts three to four years in normal use, though it varies based on how often you press the buttons. If you use the fob multiple times a day, the battery may last two to three years. If you use it rarely, it may last five years or longer.

What if I put the battery in upside down?

The fob straightforward will not work. The battery will not make electrical contact if the positive side faces the wrong direction. Open the case again, flip the battery, and close it. There is no risk of damage from installing it backward — it just will not function until you correct it.

Can I use a different battery type, like a CR2016 or CR2020?

No. Different coin-cell batteries have different thicknesses and voltages. Using the wrong type may not fit in the holder, or it may fit but not make proper contact. Stick with the type your fob is designed for — CR2032 or CR2025 for most Subaru models.

Should I replace both batteries if I have two key fobs?

Only if both fobs are not working. If one fob works fine, its battery is still good. Replace only the fob that is dead. If you want to be cautious and both fobs are old, replacing both at the same time means you are less likely to have a dead fob later.