Volvo S80 key fob battery

Separate remote fob

1. This remote is its own fob, separate from the metal key, which makes it one of the easier ones to open.
2. Look for a screw on the back or a notch on the edge. Remove the screw if present, then twist a coin in the notch to split the case.
3. Swap the cell or cells, keeping the same side up as the old ones.
4. Snap the case shut and watch for the lights to flash when you press lock 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.

Flip key

1. Fold the blade out so it is out of the way, or keep it folded if your case opens from the side; the battery sits in the plastic body, not the blade.
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. Take out the old cell, noting which side faced you, and fit the new one the same way.
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. Most push-button fobs hide a metal backup key. Press or slide its catch and draw the key out first.
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. Before you take the old cell out, look at its face. Put the new cell in with the same side showing, and avoid touching both faces at once.
4. Snap the halves back together, slide the metal key home, and press each button, then try the start button from the driver's seat.

This key takes two CR2430 cells. Change both at the same time and stack them the way the old pair sat; mixing a fresh cell with a tired one shortens the life of the new one.

A CR2430 is 24.5 mm wide and 3.0 mm thick. It is not the same as a CR2450, which is thicker.