Ford Transit key fob battery

Key with remote in the head

1. The remote electronics sit in the plastic head of the key itself, so there is no separate fob to open.
2. Find the seam around the head. Twist a coin or small flat screwdriver in the notch at the blade end or side until the halves part.
3. Inside you may find a small circuit board in a tray. Lift the board out if the cell is underneath, swap the cell with the same side up, and refit the board.
4. Snap it closed and press each button. The car still starts with a dead remote battery on most of these keys, because the start chip needs no battery.

A CR2032 is 20 mm across and 3.2 mm thick. CR2032, CR2025 and CR2016 share the same width but not the same thickness, so a swap between them can leave a loose contact or a case that will not close.

Flip key

1. Swing the key blade open first. On most flip keys the cell lives in the body behind the hinge.
2. Some flip keys have a screw on the back; others just clip. Remove the screw if there is one, then pry gently at the seam.
3. Lift the cell out with a plastic tool and press in the new one with the + side matching.
4. Close it up, check the blade still flips cleanly, and test the buttons at the car.

A CR2032 is 20 mm across and 3.2 mm thick. CR2032, CR2025 and CR2016 share the same width but not the same thickness, so a swap between them can leave a loose contact or a case that will not close.

Smart key (push-button start)

1. Start by freeing the hidden metal key: there is a latch or slide on the case, and the blade comes out once it moves.
2. Look inside the empty key slot for a notch. Put the tip of the metal key or a small flat screwdriver wrapped in tape there and twist gently until the shell splits.
3. Note which side of the old coin cell faces up (usually the side with the writing), lift it out with a plastic tool, and press the new one in the same way.
4. Reassemble, refit the emergency key, and check that the car sees the fob when you press start.

Ford intelligent access fobs usually have a release for the emergency key. The key blade itself fits the pry slot.

A CR2450 is 24.5 mm across and 5.0 mm thick, much fatter than a CR2032. A thinner cell will rattle and lose contact, so buy the exact size.