How To Change A Car Key Battery? - All Pro Locksmiths

All Pro Locksmiths • May 17, 2023

You’re in a rush to get to work. You click your car key fob to unlock the door, but nothing! Your car key battery is dead, so how do you replace it? Fear not! Changing the battery in your car key is a simple task you can easily carry out at home. In this article, we’ll guide you through the process of replacing a car key battery, so your fob will once again work.

Open The Battery Compartment

How you open the battery compartment will depend on the make and design of your car key fob.


  • Move the Key Out of the Way: If the key is housed within the fob, make sure to move it out of the way to access the battery. Certain key fobs are designed to store the key inside when not in use. For these types of fobs, either slide the key out or press a button to swing it to the top of the fob.
  • Remove the Back of the Key Fob: Older car models often have a screw holding the back and front half of the fob together. In this case, flip your key fob over and look for a tiny screw in the plastic and use a small screwdriver to remove it. Other key fobs will have a small indentation or slot along the side seam of the fob. Use a small flathead screwdriver or coin and insert it into the indentation. Rotate and twist it upwards to detach the back of the fob.


Replace Your Car Key Battery

  • Remove the Old Battery: Most car key batteries look like a small, silver coin and are usually located in the middle of the fob. Simply slip the end of flathead screwdriver under the battery and lift it out of the fob. Recycle your old car key battery by depositing it at a local battery collection site.
  • Insert the New Battery: Check the back of your fob’s cover or battery compartment to see whether the positive or negative side of the battery faces up. Using this as a guide, slide the battery into the designated slot and press it down to secure it.
  • Close the Battery Compartment: Put the cover back on the fob and press down to snap it back into place. If the back half of your fob was attached with a screw, use a screwdriver to fix the halves back together.
  • Test the Car Key Battery: Finally, test your car key by attempting to lock and unlock your vehicle. If the fob functions correctly, congratulations, you’ve successfully replaced your car key battery!

Still Having Issues With Your Car Key Battery?

Contact All Pro Locksmiths today! Our friendly team can travel to your location and provide onsite services to fix smart keys and car key fobs. Servicing the greater Port Macquarie area, our team of expert locksmiths have a keen knowledge of smart locks, fobs, remotes, immobilisers and more. With 30 years of combined industry experience, our services cost a fraction of the price your dealership would charge.

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