You can replace a Toyota key fob battery yourself in about five minutes with no tools
Most Toyota key fobs use a coin-cell battery — usually a CR2032 or CR2016 — that you can swap out at home without taking the fob apart or visiting a dealer. The battery typically lasts three to four years depending on how often you use the fob. When your fob stops locking or unlocking the car reliably, or the buttons feel sluggish, a dead battery is usually the cause.
The process is straightforward: you pry open the fob case with a coin or flat object, remove the old battery, drop in a new one the same size, and snap the case shut. You do not need a screwdriver, special tools, or a trip to the dealership. A replacement battery costs between $3 and $8 at any drugstore, grocery store, or hardware store.
Key Takeaways
- Toyota key fobs almost always use a CR2032 or CR2016 coin-cell battery that you can buy at any drugstore or supermarket for $3 to $8.
- You open the fob by sliding a coin into the slot on the edge and twisting gently until the case pops apart — no screwdriver needed.
- The battery sits in a small metal holder; note which side faces up before you remove it, then place the new battery the same way.
- After you snap the case back together, test the lock and unlock buttons before you put the fob away to make sure the new battery works.
Finding the slot and opening the fob
Look at the edge of your key fob for a small slot or seam running around the perimeter. On most Toyota fobs, this slot runs along one edge — often the side where the key ring attaches. The slot is usually narrow enough that you cannot fit your fingernail into it, which is why you need a coin.
Insert a coin — a dime, penny, or quarter works — into the slot and twist gently. You are not trying to force it; a small amount of pressure is enough. The case will pop apart into two halves. Set the metal spring and any small plastic pieces aside on a clean surface so you do not lose them. Some fobs have a small spring that helps the case stay together; if it falls out, you will need to put it back when you reassemble.
Identifying and removing the old battery
Inside the fob you will see a small metal holder or clip holding a round, flat battery. The battery is usually silver or gold in color and about the size of a dime. Before you remove it, look at which side is facing up — the side with the + symbol or the flat side. This matters because the battery only works one way.
Gently pry the battery out of its holder using the edge of your coin or a fingernail. Do not force it; it should come out with light pressure. Once it is out, you can throw it away or take it to a battery recycling program if your area has one.
Buying and installing the replacement battery
Take the old battery with you to the store so you can match the size and model number. Most Toyota key fobs use either a CR2032 or CR2016. The number tells you the size: CR2032 is slightly thicker than CR2016. If you cannot read the old battery, a store employee can help you find the right one by looking at your fob.
When you get home, place the new battery into the metal holder with the same side facing up as the old one was. If the + symbol was facing up before, make sure the + symbol faces up now. Press gently until the battery sits flat in the holder. If it does not sit flush, you may have it upside down — flip it and try again.
Closing the fob and testing it
Line up the two halves of the fob case and press them together firmly until you hear or feel a click. The case should close evenly with no gaps. If the spring fell out when you opened it, you may need to hold it in place as you close the case, or it may pop back in on its own.
Before you put the fob away, stand near your car and press the lock button. You should hear the doors lock. Press unlock and listen for the doors to unlock. If the buttons work, you are done. If nothing happens, open the fob again and check that the battery is sitting flat in its holder and facing the right direction.
What to do if the fob still does not work
If you installed a new battery and the fob still does not respond, the problem is likely not the battery. Water damage, a broken button, or a damaged circuit board inside the fob can cause the same symptoms as a dead battery.
You have two options: buy a replacement fob online or at a Toyota dealership, or take the fob to a dealership to have it repaired. Replacement fobs typically cost between $150 and $300 depending on the model year, though some dealerships charge less if you bring in the old fob. If you buy a replacement fob, the dealership will need to program it to your car, which usually takes 15 to 30 minutes and may cost an additional $50 to $100.
Frequently Asked Questions
Where do I buy a CR2032 or CR2016 battery?
Any drugstore, supermarket, or hardware store carries coin-cell batteries in the pharmacy or electronics section. Walmart, CVS, Walgreens, and Target all stock them. You can also order them online from Amazon or eBay. A single battery usually costs $3 to $8, though buying a pack of two or four is often cheaper per battery.
Can I use a different battery size if I cannot find the exact one?
No. A CR2032 and CR2016 look similar but have different thicknesses, and using the wrong size can damage the battery holder or cause the fob to malfunction. Always match the model number on the old battery or ask a store employee to help you find the exact replacement.
What if I lost the old battery and do not know what size to buy?
Bring your fob to a store that sells batteries and show it to an employee. They can open it and tell you the size, or they can install the battery for you while you wait. Some stores do this for free; others charge $5 to $10.
Do I need to reprogram the fob after I change the battery?
No. Changing the battery does not erase the fob's programming. Once you install the new battery and close the case, the fob should work when ready without any reprogramming.
How long does a new battery last?
Most coin-cell batteries in key fobs last three to four years with normal use. Heavy use — pressing the buttons many times a day — can shorten the lifespan. You will know it is time to replace it again when the fob becomes sluggish or stops working from a distance.