Most Cadillac key fobs use a CR2032 or CR2025 coin-cell battery that you can replace yourself in under a minute

Your Cadillac key fob stops working because the battery inside has drained, not because the fob itself is broken. The battery type depends on your model year and fob design — most Cadillacs from the last 15 years use either a CR2032 (the most common) or a CR2025 coin-cell battery. Both are standard sizes you can buy at any drugstore, grocery store, or hardware retailer for between $3 and $8.

The replacement process requires no tools for most Cadillac fobs. You pry open the fob with a coin or your fingernail, note which side of the battery faces up, remove the old battery, and insert the new one in the same orientation. The whole job takes about 60 seconds. If your fob has a screw holding it together instead of a snap-together case, you will need a small Phillips or flathead screwdriver.

Key Takeaways

  • Cadillac key fobs typically use CR2032 or CR2025 coin-cell batteries, which cost $3 to $8 and are sold at most retailers.
  • Most fobs open by prying the two halves apart with a coin; a few models have a small screw you must remove first.
  • The battery orientation matters — the positive side (marked with a +) must face up or down consistently with how the old one sat.
  • If the fob still does not work after you install a fresh battery, the problem is likely a worn button contact or internal damage, not the battery itself.

Finding the right battery size for your Cadillac model

The battery type is printed on the old battery itself once you open the fob. If you want to know before you open it, check your owner's manual — most Cadillac manuals list the battery type in the key fob section. You can also call your Cadillac dealer with your vehicle identification number (VIN) and model year, and they will tell you the correct battery in seconds.

CR2032 is by far the most common. It is a flat coin about the size of a dime but thicker. CR2025 is slightly thinner but the same diameter. Both fit in most modern Cadillac fobs, but using the wrong one can cause the fob to close improperly or put pressure on the battery contacts. When in doubt, match the number on your old battery exactly.

How to open your Cadillac key fob

Look at the seam running around the edge of your fob. On most Cadillac fobs, this seam is where the two plastic halves meet. Insert a coin (a quarter or dime works well) or a flat object like a butter knife into the seam and gently twist. The two halves will separate. Do not force it — if it does not give after light pressure, you may have a screw-together model instead.

If your fob has a small screw visible on the back or side, use a Phillips or flathead screwdriver (usually size 00 or 000) to remove it. Once the screw is out, the halves will separate by hand or with light prying. Keep the screw in a small dish so you do not lose it.

Once the fob is open, you will see the battery sitting in a small metal or plastic holder. Note which side faces up — this matters for the new battery. The positive side of the battery (marked with a +) should face the same direction as the old one did.

Removing the old battery and installing the new one

Gently lift or pry the old battery out of its holder. If it is stuck, use a plastic spoon or the edge of a coin to nudge it. Do not use a sharp metal object that could damage the holder or the circuit board underneath.

Before you touch the new battery, check the orientation of the old one one more time. If the + side faced up, the + side of the new battery should also face up. Slide the new battery into the holder in the same position. It should sit flat and snug without forcing.

Close the fob by pressing the two halves together until they snap. If your fob had a screw, replace it now. Test the fob by pressing each button — the lock, unlock, and panic buttons should all work. If nothing happens, open the fob again and check that the battery is seated properly and facing the correct direction.

What to do if a new battery does not fix the problem

If you installed a fresh battery and the fob still does not work, the battery was not the issue. The problem is usually worn button contacts, water damage inside the fob, or a broken circuit board. These are not repairs you can do at home.

Your options are to buy a replacement fob from a Cadillac dealer (usually $150 to $400 depending on the model) or from an aftermarket supplier (usually $30 to $100). Some aftermarket fobs require programming to your vehicle; your dealer can do this, or some locksmiths can as well. A few Cadillac models allow you to program a new fob yourself using a sequence of key turns and button presses — your owner's manual will say if yours is one of them.

Where to buy replacement batteries

CR2032 and CR2025 batteries are sold everywhere: drugstores like CVS and Walgreens, grocery stores, hardware stores like Home Depot and Lowe's, and online retailers like Amazon. You can also buy them at Cadillac dealerships, though the price is usually higher ($8 to $12 versus $3 to $5 elsewhere).

Buy a name-brand battery if you can — Energizer, Duracell, and Panasonic are reliable. Generic or store-brand batteries work fine too, but they may not last as long. A single battery usually keeps a key fob working for three to four years, depending on how often you use it.

Frequently Asked Questions

Can I use a different battery size if I do not have the exact one?

No. Using the wrong size can prevent the fob from closing properly, damage the battery contacts, or cause the fob to stop working. Always match the number on your old battery. If you cannot find the exact size, call your Cadillac dealer or check your owner's manual before you buy.

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

No. Replacing the battery does not erase any programming. The fob will work exactly as it did before once you install the new battery. Programming is only needed if you buy a completely new fob.

What if the battery holder is corroded or damaged?

Corrosion usually means water got inside the fob. If the metal contacts are green or white, try cleaning them gently with a dry cloth or a pencil eraser before you install the new battery. If the holder itself is cracked or the contacts are severely corroded, the fob cannot be repaired and you will need a replacement.

How long does a key fob battery last?

Most CR2032 and CR2025 batteries last three to four years in a key fob, depending on how often you press the buttons. Heavy use can shorten this to two years. You will know it is time to replace it when the fob stops responding or only works when you press the button very hard.