How to Replace the Key Fob Battery in a Tesla Model 3

1. Put the key fob button side down on a soft surface and release the bottom cover with a small flat-bladed tool.
2. Lift the old battery out from under the retaining clips.
3. Insert the new CR2032 battery with the '+' side facing up, without touching its flat surfaces.
4. Hold the bottom cover at an angle, align its tabs with the slots on the key fob, and press until it snaps into place.
5. Test the key fob by unlocking and locking Model 3.

• A message displays on the touchscreen when the battery is low.
• Wipe the battery clean first; finger marks on the flat surfaces can reduce battery life.
• Warning: coin cell batteries can cause severe burns if swallowed, so keep them away from children.

Source: 2026 Tesla Model 3 owner's manual, PDF pages 25, 26. Steps are summarized in our own words (AI-assisted, checked against the cited pages 2026-10-18). Other model years can differ; your manual has the final word.