How to Replace the Key Fob Battery in a Ford Fusion

1. Push the release button and pull the key blade out of the remote control.
2. Twist a thin coin under the tab hidden behind the key blade head to remove the battery cover.
3. Insert a suitable tool, such as a screwdriver, in the position shown and carefully remove the old battery.
4. Install a new battery with the + facing upward.
5. Reinstall the battery cover and the key blade.

• The remote uses one coin-type three-volt lithium battery.
• Replacing the battery does not erase the programmed key from the vehicle.
• Do not wipe off grease on the battery terminals or the back of the circuit board.

Source: 2020 Ford Fusion owner's manual, PDF pages 55, 56. 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.