You can change a Cadillac key fob battery yourself in under five minutes
Most Cadillac key fobs use a coin-cell battery — typically a CR2032 or CR2025 — that you can swap out without tools or a trip to the dealer. The fob splits open along a seam, the old battery slides out, and a new one slides in. The whole job takes longer to find the seam than to do the work. You'll spend $3 to $8 on a replacement battery at any pharmacy, grocery store, or hardware store.
The exact steps depend slightly on which Cadillac model and fob generation you have, but the principle is the same across nearly all of them. This guide covers the most common types. If your fob looks different from the ones shown here, the manufacturer's manual that came with your vehicle will have the specific steps for your model.
Key Takeaways
- Cadillac key fobs almost always use a CR2032 or CR2025 coin-cell battery that costs $3 to $8 and is sold at pharmacies and grocery stores.
- The fob splits open along a visible seam; you pry it apart with a coin or flat tool, remove the old battery, and insert the new one with the positive side facing up.
- If your fob has a physical key inside, you may need to remove that key first before the battery compartment will open.
- A dead battery usually shows up as a fob that does not respond at all; if the fob works sometimes or the buttons are stuck, the problem is likely something else.
What battery your Cadillac key fob uses
The vast majority of Cadillac key fobs from the last 15 years use a CR2032 coin-cell battery. Some older or specialty fobs use a CR2025, which is slightly thinner but the same diameter. Both are 3-volt lithium batteries and cost the same. You can buy them at CVS, Walgreens, Target, Walmart, or any hardware store — they're usually in the watch battery or electronics section, sometimes near the checkout counter.
If you're not sure which one your fob takes, check the manual that came with your vehicle, or open the fob and look at the battery itself — the model number is printed right on it. You can also call a Cadillac dealer with your vehicle's year and model, and they'll tell you in 30 seconds. Do not guess; putting the wrong battery in can damage the fob's circuit board.
Buy a fresh battery from a store, not online, so you can test it when ready. Batteries sit in warehouses and on shelves for months; a new one from a pharmacy is more likely to have full charge.
How to open your Cadillac key fob
Look at the edge of your fob for a thin seam running around the perimeter. This is where the two halves split. On most Cadillac fobs, the seam runs horizontally across the middle, or vertically down one side. You'll see a small slot or notch on one edge — this is where you insert a coin or flat tool to pry the fob open.
Use a flathead screwdriver, a coin (a dime or penny works), or a plastic pry tool. Insert it into the slot and twist gently to separate the two halves. Do not force it; if it doesn't budge, you may be prying in the wrong spot. Rotate the fob and try the other edges. Once you find the right seam, it will pop open with light pressure.
If your fob has a physical key attached to it, you may need to remove that key first. Look for a small button or tab on the back of the fob near where the key slides in. Press or slide it, and the key will eject. Then proceed with opening the fob along the seam.
Removing and replacing the battery
Once the fob is open, you'll see the battery sitting in a small metal or plastic holder. The battery is round and flat, about the size of a dime. Note which side is facing up — the positive side (marked with a + symbol) should be facing toward you. Gently pry the old battery out with your fingernail or a plastic tool. Do not use a metal screwdriver; you can scratch the circuit board.
Slide the new battery into the holder with the positive side facing the same direction as the old one was. The battery should sit flat and snug. If it's loose or tilted, remove it and reposition it. Close the fob by pressing the two halves together until you hear or feel a click. If your fob has a removable key, slide it back in until it clicks.
Test the fob when ready by pressing each button. The lock and unlock buttons should respond right away. If nothing happens, open the fob again and check that the battery is seated correctly and facing the right direction. If the fob still doesn't work after you've reseated the battery, the problem is likely a worn circuit board or button contact, not the battery itself.
When a new battery doesn't fix the problem
A completely dead fob that doesn't respond to any button press is almost always a battery issue. But if your fob works sometimes, works only when you press hard, or locks the car but won't unlock it, the battery may not be the culprit. These symptoms usually point to worn button contacts or a failing circuit board.
If you've installed a fresh battery and the fob still doesn't work, try cleaning the battery contacts. Remove the battery again and look at the metal contacts inside the fob — they may be corroded or dirty. Wipe them gently with a dry cloth or a pencil eraser, then reinsert the battery. This fixes intermittent problems about half the time.
If cleaning doesn't help, the fob's internal circuit or buttons are likely worn out. At that point, you have two options: buy a replacement fob from a Cadillac dealer (usually $150 to $300, sometimes less if you have an older model), or buy an aftermarket fob online ($30 to $80) and have a dealer program it to your vehicle. Some newer Cadillacs allow you to program a fob yourself using a sequence of key turns in the ignition; check your manual to see if yours does.
How to know if your battery is actually dead
Key fob batteries usually last three to four years with normal use. If your fob has been in a hot car, a pocket, or a bag for years without being used, the battery may have drained or corroded. Signs of a dead battery include no response from any button, a very weak response that only works from a few feet away, or buttons that work only after you press them hard.
If your fob is brand new or was working fine yesterday, a dead battery is unlikely. Check instead whether the car's battery is dead (a dead car battery can prevent the fob receiver from working), or whether you've accidentally locked the fob out by pressing buttons too many times in a row. Most Cadillacs have a safety feature that disables the fob for 30 seconds after five or six rapid button presses to prevent accidental locking. Wait a minute and try again.
Storing your key fob to keep the battery alive longer
Key fob batteries drain faster in heat and humidity. Keep your fob in a cool, dry place — not in a hot car, a bathroom, or a pocket next to your body. If you have a spare fob, rotate between them so each one sits unused for long stretches. A fob that's not being pressed will hold its charge for years.
If you won't be using your car for more than a month, consider removing the battery from your fob and storing it separately. This prevents slow drain from the circuit board drawing power even when the fob is off. When you're ready to use the car again, pop the battery back in.
Frequently Asked Questions
Can I use a different battery if I can't find a CR2032?
No. A CR2032 and a CR2025 are interchangeable because they're the same voltage and diameter, but other batteries like AA, AAA, or button batteries of different sizes will not fit or will damage the fob. Stick to CR2032 or CR2025. If your local store is out, order online or try another store — these batteries are stocked everywhere.
Do I need to reprogram my 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 will work when ready without any reprogramming steps.
What if I drop the battery or lose it while changing it?
Coin-cell batteries are small and straightforward to lose. If you drop it, look on the floor or inside the fob casing. If you can't find it, buy a new one — they cost $3 to $8. Do not try to reuse a battery that's been dropped or exposed to dirt, as it may not make good contact inside the fob.
How do I know which side of the battery goes up?
The positive side (marked with a + symbol) should face toward you when you're looking at the open fob. The negative side faces the metal contact inside the fob. If you put it in backward, the fob won't work, but it won't damage anything — just flip the battery over and try again.
Can I clean the fob while it's open to make it work better?
Yes. While the fob is open, you can gently wipe the battery contacts and the button contacts with a dry cloth or pencil eraser to remove dust or corrosion. Do not use water or cleaning solution. Let everything dry completely before reassembling the fob.