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  • Max Kelly

How to Change a Car Key Battery

Car key fobs have become an essential part of our lives, providing convenience and security. However, when the battery in your car key begins to weaken, it's important to know how to replace it. This blog post will guide you through the process of changing a car key battery. This will ensure you can continue to use your key with ease.

Can I Change My Car Key Battery Myself?

Although it is feasible to change the battery yourself, there are major risks of breaking the key and inflicting damage.


We do not recommend attempting to change the battery yourself because of the possibility of causing damage to the interior of your key, especially if you lack the requisite talents and experience.


In this case, one of our Auto Locksmiths will be able to help. We stock a wide range of batteries and can replace them whether we come to you, or you come to our drop-in service!



A Step-by-Step Guide: How to Change a Car Key Battery


Step 1: Determine the Key Type

Different car keys have varying methods of accessing and replacing the battery. Start by identifying your key type: traditional key fob, switchblade-style key, or smart key with a proximity sensor.


Consult your car's instruction manual or do a quick online search to determine the specific steps for your key type.

Step 2: Gather the Necessary Tools

Before diving into the battery replacement process, make sure you have the right tools on hand. Typically, you'll need a small flathead screwdriver and the replacement battery (usually a CR2032 or CR2025.

There are different types of batteries. To replace the key fob correctly, identify the right battery first. This information may be stated in your cars owner’s manual.

Step 3: Open the Key Fob

Once you have the necessary tools, it's time to access the battery compartment. Look for a small slot or a seam along the edges of your key fob to open the fob. Insert the flat bladed screwdriver to gently pry open the key fob. Be cautious not to apply excessive force to avoid damaging the key or its components.



how to replace a car key battery infographic

Step 4: Remove the Old Battery

Inside the key fob, you'll find the battery placed in a holder or clipped in. Carefully remove the old battery by gently pushing it out or unclipping it, depending on the design. Take note of the battery's orientation to ensure you install the new battery correctly.

Step 5: Install the New Battery

With the old battery removed, take the new battery, and align it correctly within the holder or clip. Make sure the positive (+) side faces up and matches the markings in the key fob. Firmly press the battery down until it is securely in place. Double-check that the battery is properly installed to ensure reliable functionality.

Step 6: Reassemble and Test

  1. Install the new battery.

  2. Align the halves of the fob.

  3. Apply gentle pressure until it snaps shut.

  4. Test the key by pressing the buttons to verify that the new battery is functioning correctly. If this works, you have successfully changed the battery in your car key and should be able to unlock your car!

If your car battery is not working or you are still having problems locking and unlocking, it may need to be replaced. You can call an Auto Locksmith to do this. They specialise in key fob battery replacement, so they can ensure your key is fully functional again.




How To Know If My Car Key Battery Needs to Be Replaced?

One of the first indicators of a low car key battery is decreased range or responsiveness. You may notice that your key requires more effort by pressing the button repeatedly to lock or unlock the doors, or that the distance from which you can operate the key has diminished. If you experience any of these issues, it's advisable to consider a battery replacement.

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