How to Replace a Car Key Battery

Updated April 17, 2017

Many vehicles now come with a remote keyless entry system as part of the car key. These remotes will eventually require battery replacement. Knowing how to replace the battery in your remote keyless entry car key can save you time and money.

Purchase a new replacement battery. Check your vehicle's manual to determine the correct type and size of battery to purchase. Alternatively, most technicians at larger auto parts stores can pull up the requirements for your vehicle on their computers to help you make this purchase.

Determine how to open your remote keyless entry car key. Different keys require different opening methods. One method involves grabbing the sides of the key and lightly pulling until the key separates into two pieces. Another method involves locating and pressing a release tab that opens the back panel on the key. A third method involves using a small Phillips screwdriver to remove the small screws holding the two key panels together.

Find the battery located in the interior area of the key. The battery is small, round and metallic in appearance.

Remove the battery.

Place the new battery inside the battery slot. Make sure that the plus side of the battery is facing out.

Replace the outer panel of the key. Make sure the panel is replaced properly to ensure the battery is secure. Use the method you followed in Step 2 to open your remote keyless entry car key, but in reverse.

Test the new remote keyless entry car key battery to ensure that it functions properly.


Always make sure the replacement battery is positioned correctly in the battery slot. If the battery faces the wrong way, it will not function.

Things You'll Need

  • Replacement battery
  • Small Phillips screwdriver
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About the Author

Based in Alabama, Stephanie Busby Davis has been writing and researching since 2001, primarily in areas such as communication studies, business and the entertainment industries. Her articles have appeared in "NCA Spectra" and numerous other publications. Davis holds a Master of Arts in communication studies from the University of South Alabama.