What battery your 2015 MKZ key fob uses and where to find it

Your 2015 Lincoln MKZ key fob uses a CR2032 coin cell battery, the same type found in watches, calculators, and many other small devices. You can buy CR2032 batteries at any drugstore, supermarket, or big-box retailer in the battery aisle — they typically cost between $3 and $8 for a pack of two or four. You do not need to visit a dealership or a specialty shop.

Before you start, gather what you need: a CR2032 battery, a small flathead screwdriver or a coin (a dime or penny works), and a clean, flat surface to work on. The whole job takes about five minutes.

Key Takeaways

  • Your 2015 MKZ key fob takes a CR2032 battery, sold at any drugstore or supermarket for a few dollars.
  • The fob splits open along a seam on the side — use a coin or small flathead screwdriver to pry it apart gently.
  • The battery sits in a metal holder; note which side faces up before you remove it, then slide the new one in the same way.
  • After you close the fob, test all buttons to make sure the new battery is working before you put the fob away.

How to open the key fob without damaging it

Look at the edge of your key fob and find the thin seam that runs around the middle — this is where the two halves split apart. The seam is usually on the side opposite the panic button. Insert a coin (a dime or penny) or a small flathead screwdriver into the seam and twist gently. Do not force it; you are looking for the fob to pop open slightly, not to crack.

Once you feel it start to give, work your way around the seam, twisting a little at a time, until the two halves separate. The top half (the one with the buttons) will come away from the bottom half (the metal backing). Set the top half aside somewhere safe so you do not lose the small springs or contacts inside.

Removing and replacing the old battery

Inside the bottom half of the fob, you will see the CR2032 battery sitting in a metal holder. The battery is round and flat, about the size of a dime. Before you touch it, note which side is facing up — the positive side (marked with a + sign) should be facing toward you. This matters because the battery only works one way.

Slide the old battery out of its holder by tilting it slightly and lifting it away. Drop the new CR2032 battery into the holder with the positive side facing the same direction as the old one was. The battery should sit flat and snug in the holder; if it is loose or tilted, remove it and try again.

Closing the fob and testing it

Line up the two halves of the fob so the seam matches up evenly all the way around. Press down firmly and evenly until you hear or feel a click — the fob should snap shut and feel solid, not loose or wobbly. If it does not close all the way, open it again and check that the battery is sitting flat and that nothing is blocking the seam.

Once the fob is closed, test each button — lock, unlock, and panic if your fob has one. You should see the red light on the fob blink when you press a button, and your car should respond. If nothing happens, open the fob again and check that the battery is facing the right direction and sitting firmly in the holder.

When the battery is not the problem

If you installed a new battery and the buttons still do not work, the issue is usually not the battery itself. The most common cause is that the battery is not making good contact with the metal holder — open the fob again and make sure the battery is sitting flat and centered. If the holder looks dirty or corroded, wipe it gently with a dry cloth.

If the fob still does not work after you have checked the battery twice, the problem may be inside the fob — a broken button contact, a damaged circuit board, or a loose wire. At that point, a dealership can test the fob and tell you whether it can be repaired or needs to be replaced.

Frequently Asked Questions

Can I use a different battery instead of CR2032?

No. The CR2032 is the only battery that fits your 2015 MKZ key fob and provides the correct voltage. Other coin cell batteries like CR2025 or CR2016 are slightly thinner and will not make proper contact with the holder. Always use CR2032.

What if I put the battery in backwards?

The fob straightforward will not work. The battery only conducts electricity one way. If you close the fob and nothing happens when you press the buttons, open it again and flip the battery so the positive side faces the same direction as before. This is the most common mistake.

How often do I need to replace the battery?

Most CR2032 batteries last two to four years in a key fob, depending on how often you use it. You will know it is time when the buttons stop responding or the red light becomes very dim. There is no set schedule — just replace it when it stops working.

Is it safe to throw away the old battery?

CR2032 batteries contain lithium and should not go in the regular trash. Most drugstores and supermarkets have a battery recycling bin near the customer service desk or in the parking lot. You can also take old batteries to an electronics recycling center.