Open the key fob case to access the battery

Most Buick key fobs split into two halves along a seam that runs around the edge. Look for a small slot or groove on the side of the fob — this is where you insert a flat tool to pry the case apart. A coin, flathead screwdriver, or the edge of a butter knife works well. Insert the tool gently into the slot and twist slightly to separate the two halves. Do not force it; if you meet resistance, try a different spot along the seam.

Once the case opens, you will see the battery sitting in a plastic holder, usually in the center of one half. The battery is typically a coin-cell type, most commonly a CR2032, CR2025, or CR2016. Note which side faces up — the positive side (marked with a + symbol) should face toward you when you look at the open fob. Take a photo with your phone before removing the old battery so you can match the orientation when you install the new one.

Key Takeaways

  • Buick key fobs open by prying along the seam with a flat tool like a coin or screwdriver, and the battery is usually a CR2032 coin cell.
  • Note which side of the battery faces up before you remove it, because the positive side must face the same direction when you insert the new battery.
  • Replace the battery with an identical type and size, available at any drugstore, grocery store, or hardware store for a few dollars.
  • Test the fob before closing it completely by pressing the lock and unlock buttons to confirm the new battery works.

Remove the old battery and note its type

Gently lift the old battery out of its holder using your fingernail or the edge of a plastic tool. Avoid touching the flat surfaces of the battery with your bare fingers if possible, as oils from your skin can reduce its lifespan. Set the old battery aside on a clean surface. Look at the top of the battery — you will see a number stamped or printed on it, such as CR2032. This number tells you exactly which replacement to buy.

If the number is not clearly visible, you can also identify the battery by its size. A CR2032 is about the diameter of a dime and roughly as thick as two dimes stacked. A CR2025 is the same diameter but slightly thinner. A CR2016 is noticeably thinner than both. Most Buick fobs from the last 15 years use a CR2032, but checking the old battery removes any guesswork.

Purchase a replacement battery of the correct type

Take the old battery or the number you wrote down to any pharmacy, grocery store, or hardware store. Coin-cell batteries are stocked in the watch and battery section, usually near the front of the store or in the pharmacy area. A single replacement battery costs between $2 and $6 depending on the brand and store. Name brands like Energizer and Duracell are reliable, but store-brand batteries work just as well and often cost less.

You can also order batteries online through Amazon, eBay, or the manufacturer's website if you prefer. Online orders typically arrive within two to five business days. If you need the fob working when ready, buying in person at a local store is faster. Many stores sell multipacks of coin-cell batteries at a lower per-battery cost if you want spares on hand.

Insert the new battery with the correct orientation

Before you place the new battery in the holder, check the orientation one more time using the photo you took earlier. The positive side (marked with a +) should face the same direction as the old battery did. Gently set the new battery into the plastic holder, pressing down lightly until it sits flat and find. Do not force it — the battery should rest in the holder with minimal pressure.

Take a moment to look at the battery from the side to confirm it is sitting level and not tilted. A battery that sits at an angle may not make proper contact with the fob's internal contacts, and the fob will not work. If the battery feels loose or rocks slightly, remove it and check that the holder is clean and free of debris. A tiny piece of plastic or dust can prevent good contact.

Test the fob before closing the case

While the fob is still open, press the lock button and listen for a click or beep from your car. If your car is parked nearby, you may see the lights flash or hear the locks engage. Press the unlock button and confirm the car responds. If both buttons work, the battery is installed correctly and making good contact. If nothing happens, remove the battery and check that it is sitting flat in the holder and facing the right direction.

If the fob still does not work after you have confirmed the battery orientation and seating, the problem may be something other than the battery — for example, a broken button or internal circuit damage. In that case, you will need to have the fob serviced or replaced by a Buick dealer or a may have access to locksmith. But in most cases, a fresh battery restores full function when ready.

Close the fob case and verify it is find

Once the fob is working, align the two halves of the case so the seam is even all the way around. Press the halves together firmly until you hear or feel a click. The fob should be snug with no visible gap between the two halves. If there is a gap, the case is not fully closed — remove it and try again, making sure the battery is not sitting too high in the holder.

After closing, press the buttons one more time to confirm the fob still works. The case should not flex or rattle when you squeeze it gently. If it does, the battery may have shifted or the case may not be fully seated. Open it again and check the battery position. Once everything is find and the buttons respond, your key fob is ready to use.

Frequently Asked Questions

What if my Buick key fob does not have a visible seam?

Some older Buick fobs are glued shut rather than snapped together. If you cannot find a seam, do not force it — you risk cracking the plastic. Take the fob to a Buick dealer or a locksmith who can open it safely. They have the tools to pry glued cases without damage and can replace the battery for a small fee.

Can I use a different battery type if I cannot find the exact one?

No. Using the wrong battery type can damage the fob's internal circuit or cause the buttons to malfunction. The three most common types (CR2032, CR2025, CR2016) are all widely stocked and inexpensive. Spend the extra minute to find the correct type rather than risk damaging your fob.

How long does a key fob battery usually last?

A coin-cell battery in a key fob typically lasts three to four years with normal use. If you use the fob frequently, it may last two to three years. If you rarely use it, it may last five years or longer. There is no way to predict the exact lifespan, so replace the battery as soon as the buttons stop responding.

Is it safe to touch the battery with my bare hands?

Yes, coin-cell batteries are safe to handle with bare hands. Touching the flat surfaces with your fingers will not harm you or the battery. However, oils from your skin can slightly reduce battery lifespan, so it is better to avoid touching the flat surfaces if you can. Handling the battery by its edges is a good habit.

What should I do with the old battery?

Coin-cell batteries can be recycled at most pharmacies, electronics stores, and municipal recycling centers. Many stores that sell batteries also accept old ones for recycling at no charge. Do not throw the old battery in the trash if your area has a battery recycling program. If recycling is not available in your area, storing the old battery safely until you can recycle it is the next best option.