If you’ve noticed a “Key battery needs replacing” message on your dash don’t worry, your car battery is fine. What that means is that it’s time to replace the small battery inside the key fob. Luckily, it’s a simple fix and should only take a few minutes. The process is slightly different between the Model S and X fobs, so first we’ll go over the Model S.
- 3v 2032 lithium battery
- Small flathead screwdriver
To open the battery cover, push against the small notch in the middle of the fob next to the S until the cover releases.
Then pry out the battery, noting the orientation of the “+” and “-“.
Insert the new 3v battery and slide the cover back until it snaps into place.
For the Model X:
- 3v CR2354 lithium battery
Using the paperclip or a pen, find the small notch on the “X” side of the fob and press into the notch. This will release the cover.
Once the battery is exposed pry out the old battery noting which way the positive end is facing.
Replace the battery and reinsert the cover by lining up the “Model” side, then pressing the “X” side into place until it clicks.
The last step is clear the alert message from the dash. Simply take both key fobs with you into the driver’s seat and the alert should disappear.