Mazda Mazda6 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. Turn it over: some older fobs use one small screw, newer ones just clip. Pry at the seam once any screw is out.
3. Replace the cell, keeping the + side where it was, and check the small metal tab still touches it.
4. Snap the case shut and watch for the lights to flash when you press lock at the car.

A CR2025 is 20 mm across and 2.5 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. Open the flip blade. Never force the hinge sideways, since the spring and pin are the weak part of a flip key.
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. Swap the coin cell, keeping the same face up as the one you removed, and do not bend the metal contact tab.
4. Close it up, check the blade still flips cleanly, and test the buttons at the car.

A CR1620 is 16 mm across and 2.0 mm thick. It is easy to confuse with the 20 mm CR20xx sizes, which will not fit.

Smart key (push-button start)

1. Find the small release on the edge or back of the fob and hold it while you pull out the metal emergency key.
2. Use the slot where the metal key sat. Twist, do not lever hard, and work along the seam until the halves separate.
3. Pop the old battery out with a toothpick or plastic pick, not a metal blade, and seat the new one with the + side matching the old one.
4. Close the case until it clicks all the way round, put the metal key back, then try the buttons and a push-button start.

Mazda advanced keys usually have a knob or button that frees the auxiliary key; the cover lifts once the key is out.

A CR2025 is 20 mm across and 2.5 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.

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.