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A simple guide to opening a key fob & adding a new battery
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As you rush off to work, you click your car’s key fob to unlock the door…but nothing happens. The battery in your fob is dead, so how do you replace it? Luckily, it’s super quick and easy to change out your old key fob battery. We’ll show you how to open your key fob, find the right battery, and insert it to get your fob back to working order. If you’re ready to learn how, read on!

Things You Should Know

  • Slide or swing out the key if it’s inside your fob and check the back of the fob for a screw. If it has a screw, unscrew it with a small Phillips head screwdriver.
  • Look for a slot or notch along the seam that separates the top and bottom halves of the fob. Push a coin or flathead screwdriver into the slot and lift up to open the fob.
  • Slide a flathead screwdriver under the coin battery to pop it out of place. Insert a new battery in the same position and snap the 2 halves of the fob closed.
Part 1
Part 1 of 2:

Opening the Fob

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  1. Some key fobs hold the key inside the fob to store it when you’re not using it. If you have this style of fob, move the key out of the way to access the battery. On most fobs, you either slide the key out or press a button to swing it to the top of the fob. [1]
    • Cars like Fords, Chevys, Dodges, and Hondas typically have key fobs with a removable key. To remove it, just hold the button on the side of the fob or push the switch on the back. Then, pull up on the silver top of the fob. [2]
    • Cars like Volkswagens typically have a key that swings out of the fob. Simply press the button on the front of the fob to extend the key to the top of the fob. [3]
  2. Some older car models, like the Honda Accord, have a screw that holds the back half of the fob to the front. Just flip your key fob over and look for a tiny screw in the plastic. If you have a screw, use a small Phillips head screwdriver to rotate the screw counterclockwise and remove it. Work slowly to avoid stripping the screw. [4]
    • Set the screw aside in a safe spot so you don’t lose it, like inside a resealable bag or small cup.
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  3. Most key fobs have a small indentation or slot along the side seam of the fob that separates the top and bottom halves. The notch might be on the top or bottom of the fob, or on either side. Simply take a small flathead screwdriver or coin and push it into the indentation. Then, turn and twist your tool up to separate the top half of the fob from the bottom. [5]
    • Work your way around the seam, continuing to turn and twist the coin or screwdriver to fully remove the fob’s halves.
    • On fobs with a removable key, look for the slot in the cavity where the key was. Then, insert the key into the notch to pry the halves apart. [6]
  4. Some key fobs might not have a slot along the seam. If you have this type of fob, simply push the tip of a flathead screwdriver or butter knife into any point on the seam. Then, lift the screwdriver to separate the halves. Continue to insert the screwdriver and lift up at different points along the seam to fully separate the halves. [7]
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Part 2
Part 2 of 2:

Replacing the Battery

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  1. Most key fob batteries look like a small, silver coin and are usually located in the center of the fob. Just slip the tip of a small flathead screwdriver or butter knife under the battery. Then, gently lift up with your screwdriver to take it out of the fob. [8]
    • Some fobs have clips over the battery, so lift the clips up with a screwdriver. Move slowly, lifting the clips as gently as possible to avoid breaking them.
    • Recycle your old batteries by searching for a battery collection site near you online.
  2. Check the back of the fob’s cover or under the battery compartment to see whether the positive or negative side of the battery faces up. Then, slide the battery into the slot and push it down to secure it into place. [9]
    • If you’re not sure which way to insert the battery, look it up in your car’s owner’s manual.
    • Check your car’s owner manual or the backside of your fob to see what type of battery you need. Most car key fobs use CR2025 or CR2032 batteries, though others, like the Honda CR-V, use a CR1620 . [10]
    • General stores, home improvement stores, and auto parts stores usually sell coin-style batteries. They typically come in packs of 2 to 6 and cost $5-10.
    • Most key fobs only take 1 battery, though some, like the Ford Mustang’s key fob, take 2.
  3. Put the cover back on the fob to cover up the battery. Then, simply push down to snap it back into place. If the back half of your fob was attached with a screw, use a screwdriver to turn it clockwise and bind the halves together. [11]
  4. Point the key fob at your car or other device and click one of the buttons. If your fob still isn’t working, you might’ve put the battery in the wrong direction. Just take the fob apart again, flip over the battery, and test the fob again. [12]
    • Most key fobs work without you having to reprogram them after replacing the battery.
    • If your fob still isn’t working after ensuring the battery is in correctly, it might be broken. Call a locksmith or your local car dealership to replace the fob .
    • Or, if you have an older car, buy a blank replacement key fob online. Then, program the fob to your car.
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How Do You Replace The Battery In a Car Key Fob?


Community Q&A

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  • Question
    Where can I get a battery for the key fob?
    i am dat skull
    Community Answer
    Fobs generally use small, coin-shaped batteries like CR2025 or CR2032. You can usually find them at general stores, home improvement stores, and some auto part stores. To find the specific type of battery yours uses, consult the owner's manual of inspect the fob and battery for a label.
  • Question
    Are the CR2025 and CR2023 interchangeable?
    Upnorth Here
    Top Answerer
    Not always. They both have 3 volts and the same diameter, but 2.3 mm of the CR2032 is not as thick as 2.5 mm of the CR2025 cell. Some devices may have adequate spring travel for the difference, but other devices will only work with the proper cell thickness.
  • Question
    Is a CR2016 the same as a CR2032 or a CR 2025?
    Upnorth Here
    Top Answerer
    No, it is not the same as either of those. For one thing, the 2016 and 2032 are different sizes, i.e., a difference of 160 micrometers in thickness. You might be able to shim a 2016 with conductive foil as a temporary substitute in some cases. Similarly, the CR2025 is 7 tenths of a millimeter thinner than a CR2032 and 9 tenths of a mm thicker than CR2016.
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      • Key fobs vary, so the battery replacement process may also vary. Consult your owner’s manual or search for your fob's manufacturer online to find more instructions.
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      Things You’ll Need

      • Phillips head screwdriver
      • Flathead screwdriver
      • New battery

      About This Article

      Article Summary X

      To replace the battery in your key fob, start by unscrewing its back with a small Philips screwdriver. Set the screw aside somewhere safe so you don’t lose it. If your fob has a small indentation along the side, push a small coin or flat head screwdriver inside and twist it to separate the halves. If there’s no indentation, push your screwdriver in the seam and pry the halves apart. Once you’ve opened your fob, replace the battery, which is usually a small coin-shaped watch battery. Finally, close your fob and secure the screw in place. For more tips, including how to replace a car key battery, read on!

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      • Eric B.

        Aug 27, 2023

        "Thanks, for the gained confidence from carefully prying the case halves apart. Carefully! And that's it! ..." more
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