Open the key fob case without damaging it

Most Nissan Altima key fobs split into two halves along a seam that runs around the edge. Look for a small slot or notch on one side of the fob — this is where you insert a flat tool to pry the case apart. A flathead screwdriver, coin, or plastic spoon works well. Insert the tool gently into the slot and twist slightly to create a gap, then work your way around the edge until the two halves separate.

Do not force the case open or use sharp tools that can slip and damage the plastic. If you cannot find a visible seam, check the back of the fob for a small button or latch that may need to be pressed before the case will open. Some older Altima fobs have a screw holding the case together — if you see one, use a small Phillips screwdriver to remove it before attempting to pry the halves apart.

Key Takeaways

  • Nissan Altima key fobs use a CR2032 battery, which you can find at any pharmacy, grocery store, or hardware store for a few dollars.
  • The battery sits in a small metal holder inside the fob and slides out or lifts straight up depending on your model year.
  • Pay attention to which side of the battery faces up when you remove it, because the replacement must go in the same way.
  • After inserting the new battery, snap the fob case back together and test all buttons before putting it away.

Identify and remove the old battery

Once the case is open, you will see a small round battery held in a metal clip or spring holder. The battery is a CR2032 — a coin-shaped cell about the size of a dime. Before you remove it, note which side is facing up. The positive side (marked with a + symbol) should be facing toward you or toward the circuit board, depending on your fob's design. Take a photo with your phone if you are unsure.

To remove the battery, gently lift the edge of the metal clip or spring that holds it in place, then slide the battery out sideways. If the clip is tight, use your fingernail or a plastic tool to lift it slightly. Do not use a metal screwdriver or anything sharp, because you can scratch the circuit board or damage the clip. Once the old battery is out, set it aside — do not throw it away yet, in case you need to check its part number.

Insert the new CR2032 battery

Before you open the new battery, wash your hands or wipe them on a clean cloth. Oils from your skin can interfere with the battery's contact with the metal clip. Slide the new CR2032 into the holder with the positive side facing the same direction as the old battery was facing. You should hear or feel a small click as the metal clip springs back over the battery and holds it in place.

If the battery does not sit flat or the clip does not hold it securely, remove it and try again. The battery should not wiggle or move when you gently push on it. If the clip is bent or damaged, the fob may not work reliably even with a fresh battery — in that case, you may need to replace the entire fob.

Close the fob case and test the buttons

Align the two halves of the fob so the seam is even all the way around, then press them together firmly until you hear a click. Start at one end and work your way around, explore steady pressure. Do not snap the case shut all at once, because you can crack the plastic or misalign the internal parts.

Once the case is closed, test each button on the fob — lock, unlock, and panic if your model has one. Point the fob at your Altima from a few feet away and press each button. You should see the lights flash on the car and hear the locks respond. If nothing happens, open the fob again and check that the battery is seated properly and facing the right direction. If the buttons still do not work after reseating the battery, the circuit board may be damaged and the fob will need to be replaced.

Where to buy a CR2032 battery

A CR2032 battery costs between $2 and $8 depending on the brand and where you shop. You can find them at pharmacies like CVS or Walgreens, grocery stores, hardware stores like Home Depot or Lowe's, and online retailers. Buy a name-brand battery like Duracell, Energizer, or Panasonic rather than a generic store brand — the extra dollar or two is worth it for reliability.

Some retailers sell CR2032 batteries in multipacks, which is a good choice if you have multiple key fobs or want to keep a spare on hand. A fresh battery should power your key fob for three to four years under normal use. If your fob stops working again within a few months, the problem is likely not the battery but a damaged circuit board or worn button contacts.

What to do if the fob still does not work

If you have replaced the battery and tested all the buttons but the fob still does not unlock or lock your car, the issue is usually one of three things: the battery is not making good contact with the metal clip, the circuit board has water damage, or the button contacts are worn out. Try removing the battery again, cleaning the metal contacts with a dry cloth, and reinserting it. Sometimes a thin layer of corrosion or dust prevents the battery from making a solid connection.

If that does not work, the fob itself may be damaged. Nissan dealerships sell replacement fobs for Altima models, and you can also find aftermarket fobs online that are cheaper. A dealership can program a new fob to your car, though some aftermarket fobs come with programming instructions you can follow yourself. Before you buy a new fob, confirm that your car's locks are working — if the doors will not unlock with the fob or with the physical key, the problem is with the car's receiver, not the fob.

Frequently Asked Questions

Can I use a different battery size if I cannot find a CR2032?

No. A CR2032 is the correct size for Nissan Altima key fobs, and using a different battery can damage the circuit board or cause the fob to malfunction. CR2032 batteries are widely available and inexpensive, so it is worth taking a few minutes to find the right one rather than substituting.

How long does a key fob battery last?

A CR2032 battery in a key fob typically lasts three to four years with normal use. If you use the fob frequently — several times a day — the battery may wear out sooner. If you rarely use the fob, it may last longer.

What if I drop the battery or lose it inside the fob case?

If you drop the battery, pick it up and inspect it for cracks or dents. A slightly dented battery may still work, but a cracked one should be discarded. If the battery falls inside the fob case, tilt the fob gently to locate it, then use a small flashlight to see inside and retrieve it with tweezers or a small tool.

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

No. Changing the battery does not erase the fob's programming. As long as the new battery is installed correctly and the circuit board is not damaged, the fob will work when ready without any reprogramming.

Is it safe to handle a CR2032 battery with my bare hands?

CR2032 batteries are safe to touch, but it is better to avoid getting skin oils on the battery contacts. Wash your hands or wipe them on a clean cloth before handling the battery, and avoid touching the flat metal surfaces on the top and bottom of the cell.