Most Toyota key fobs use a CR2032 or CR2016 coin-cell battery that you can swap yourself in under two minutes
You do not need a dealer visit or special tools. The battery compartment on a Toyota key fob opens with a coin or flathead screwdriver, and replacement batteries cost between $3 and $8 at any drugstore, supermarket, or hardware store. The whole job takes longer to find the battery aisle than to do the swap.
The exact battery type depends on your Toyota model year and fob design, but Toyota has used the same two battery sizes across most of its lineup for the past fifteen years. Once you know which one your fob needs, you can keep a spare at home so you are never stuck with a dead fob.
Key Takeaways
- Toyota key fobs typically use either a CR2032 or CR2016 coin-cell battery, both widely available at drugstores and supermarkets for under $10.
- The battery compartment opens by inserting a coin or flathead screwdriver into the slot on the fob's edge and twisting gently to separate the two halves.
- When you remove the old battery, note which side faces outward so you can install the new one the same way — the positive side usually faces up.
- After inserting the new battery and closing the fob, test all buttons to confirm the replacement worked before you leave the store.
Identifying your Toyota key fob battery type
The easiest way to find out which battery your fob needs is to open it and look at the old battery itself. The battery will have a number printed on it — CR2032 or CR2016 are by far the most common. Write down that number before you go to the store, or take a photo of the battery with your phone.
If you do not want to open the fob first, you can look up your Toyota model year and body style online. Toyota's owner portal and most automotive forums list the battery type for each generation. You can also call a Toyota dealer parts department and give them your vehicle identification number (VIN) — they will tell you the correct battery in one minute, though they may try to sell you one at dealer markup.
CR2032 batteries are thicker and hold more charge; CR2016 batteries are thinner. Both are coin-shaped and about the size of a dime. Do not guess — buying the wrong size means the battery will not sit flush in the compartment and the fob may not work.
Opening the key fob without damage
Look at the edge of your fob for a thin slot or seam running along one side. This is where the two plastic halves meet. Insert a coin (a dime or penny works well) or a flathead screwdriver into that slot, positioning it so the edge of the coin or screwdriver blade sits in the seam.
Turn the coin or screwdriver gently — do not force it. You are not trying to pry the fob apart; you are explore just enough rotational pressure to separate the two halves. The fob should pop open with minimal effort. If it does not budge after a gentle twist, try a different spot along the seam; sometimes the slot is easier to find a quarter-inch to the side.
Once the fob cracks open, you can usually pull the two halves apart by hand. Be careful not to drop the circuit board or any small springs that may be inside. Some Toyota fobs have a small metal spring or clip holding the battery in place — note where it sits before you remove the battery.
Removing and replacing the battery
Look at the battery sitting in its compartment. The side facing up is usually marked with a + symbol or is straightforward the shiny side. This is the positive terminal. Before you remove it, take a mental note of which side is facing up — or take a quick photo — so you install the new battery the same way.
Gently pry the old battery out using a fingernail, a plastic spoon, or the edge of a coin. Do not use anything sharp that could scratch the circuit board. Once the battery is out, drop the new battery into the compartment with the positive side facing the same direction as the old one was facing. If there was a metal clip or spring, make sure it sits on top of the new battery the way it did on the old one.
Press down gently on the battery to make sure it sits flat and does not rock. The compartment should feel snug but not require force. If the battery feels loose, remove it and check that you have the right size — a loose battery means you bought the wrong type.
Closing the fob and testing the buttons
Align the two halves of the fob so the seam runs evenly all the way around. Press them together firmly until you hear or feel a click. The fob should close flush with no gaps. If one side is sticking up, the battery may not be sitting flat — open it again and reseat the battery.
Once the fob is closed, press each button — lock, unlock, panic, trunk, or whatever buttons your fob has — and listen for the clicking sound that means the transmitter is firing. If you hear clicks and your car responds, the replacement worked. If you hear nothing or the car does not respond, open the fob again and check that the battery is seated correctly and facing the right direction.
If the fob still does not work after you have reseated the battery twice, the circuit board may be damaged or the battery compartment may have corrosion inside. In that case, a Toyota dealer can replace the entire fob, though the cost is usually $150 to $300 depending on the model.
Where to buy replacement batteries and what to expect
CR2032 and CR2016 batteries are stocked at nearly every drugstore, supermarket, and hardware store in the United States. Walgreens, CVS, Walmart, Target, Home Depot, and Ace Hardware all carry them in the battery aisle. Online, Amazon and eBay sell them in bulk packs of four or more for $5 to $15 per pack.
Prices vary slightly by retailer and brand. Name brands like Duracell and Energizer cost a bit more than store brands, but all coin-cell batteries are manufactured to the same standard and perform identically. A single battery from a drugstore typically costs $4 to $8; a pack of four from an online retailer costs $1 to $3 per battery.
Check the expiration date on the package before you buy. Coin-cell batteries have a shelf life of five to ten years, and an expired battery may not hold a full charge. Most retail batteries are fresh, but online bulk packs sometimes sit in warehouses longer.
Keeping your key fob working longer
A Toyota key fob battery typically lasts three to four years with normal use. You can extend that lifespan by keeping the fob away from extreme heat, moisture, and direct sunlight. Do not leave it in a hot car, in a bathroom where humidity is high, or in a pocket where it gets sat on repeatedly.
If your fob gets wet, dry it thoroughly with a soft cloth and let it sit in a warm, dry place for a few hours before using it again. If water gets inside the casing, the circuit board may corrode and the fob may stop working even after you replace the battery. In that case, you will need a replacement fob from a Toyota dealer.
Keep a spare battery at home so you can swap it in when ready if your fob dies. This is faster and cheaper than a dealer visit, and it means you always have a working fob even if one battery runs out.
Frequently Asked Questions
What if my Toyota key fob has two batteries instead of one?
Some older Toyota fobs and certain specialty fobs use two coin-cell batteries stacked on top of each other. If you open your fob and see two batteries, replace both with new ones of the same type. Make sure both are facing the same direction — positive side up — and that they sit flat against each other with no gaps.
Can I use a rechargeable coin-cell battery in my Toyota key fob?
Rechargeable coin-cell batteries exist but are not recommended for key fobs. They hold less charge than disposable batteries and may not provide enough power to transmit a signal reliably. Stick with standard disposable CR2032 or CR2016 batteries.
My fob still does not work after I replaced the battery. What should I do?
First, open the fob again and check that the battery is seated flat and facing the correct direction. If it is, try a fresh battery from a different package — the first battery may have been defective. If a second new battery does not work, the circuit board or transmitter may be damaged, and you will need a replacement fob from a Toyota dealer.
Is it safe to replace the battery myself, or should I go to a dealer?
Replacing the battery yourself is safe and does not void any warranty. You are only swapping a battery, not repairing or modifying the fob. A dealer will charge you $50 to $100 for the same five-minute job, so doing it yourself saves money and time.
How do I know when my key fob battery is dying?
The first sign is that you have to press the buttons harder or multiple times to get a response. The range also shrinks — you may have to stand closer to your car for the fob to work. If the fob stops working entirely, the battery is dead and needs replacement.