The key fob's battery lasts for approximately a year with normal use. When the battery is low, a message displays on the instrument panel. Follow these steps to replace it:

1. With the key fob placed button-side down on a soft surface, use a small flat-bladed tool or fingernail to release the bottom cover.
   Note

   If a lanyard is attached to the key fob, you can release the bottom cover by placing your thumb against the "X" on the bottom cover, then firmly pulling the lanyard toward you (hence pushing the key fob off of its cover). You can also pry the cover off by placing a small flat-bladed tool, a fingernail, or the Tesla-provided tool against the lanyard cord.
2. Remove the battery by carefully releasing it from the retaining clips at an angle.
3. Insert the new battery (type CR2354) with the ‘+’ side facing up. The battery fits snugly so you must slide it into position at an angle toward the Positive contact (the contact located near the center of the key fob), then press down firmly on the other side, ensuring it is held firmly in its intended position.
   Note

   Tesla recommends using Panasonic CR2354 batteries. These can be purchased through online retailers, local supermarkets, and drug stores.
   CAUTION

   The battery should press against the spring on the positive contact. Do not place the battery on top of the contact and force it down vertically. Doing so may damage the contact.
   Note

   Wipe the battery clean before fitting and avoid touching the battery's flat surfaces. Finger marks on the flat surfaces of the battery can reduce battery life.
4. Holding the cover at an angle, align the tabs on the widest side of the cover with the corresponding slots on the key fob, then press the cover firmly onto the key fob until it snaps into place.
5. Test that the key fob works by unlocking and locking your vehicle.