Honda Pilot 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. Lift the old coin cell out and press the new one in with matching orientation.
4. Close the fob and test it. If it does not work, open it again and check the cell is seated flat.

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.

Remote key (form not stated in the source)

1. Key shape is not stated by the source. Compare your key with the types described on the how-it-works page.
2. Find the seam and work it open slowly.
3. Replace the cell with the same side up, close the case, and test.

A CR1616 is 16 mm across and 1.6 mm thick. It is easy to confuse with the 20 mm CR20xx sizes, which will not fit.

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. Many key heads split along the side seam. Start at the small notch and pry a little at a time.
3. Replace the cell with the same face showing, and make sure the rubber keypad sits flat before closing.
4. Press the head together until it clicks and test the buttons. The transponder chip that lets the car start is separate from the battery, so starting should not change.

A CR1616 is 16 mm across and 1.6 mm thick. It is easy to confuse with the 20 mm CR20xx sizes, which will not fit.

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. Use the slot where the metal key sat. Twist, do not lever hard, and work along the seam until the halves separate.
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. Close the case until it clicks all the way round, put the metal key back, then try the buttons and a push-button start.

Honda smart keys typically have a release lever for the built-in key. Twist a coin or the key tip in the slot it exposes to split the case.

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.