Hyundai Accent 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. Swap the cell or cells, keeping the same side up as the old ones.
4. Close the fob and test it. If it does not work, open it again and check the cell is seated flat.

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. Find the seam or small slot on the body (often at the end away from the blade) and twist a coin or small flat screwdriver in it until the cover lifts.
3. Lift the cell out with a plastic tool and press in the new one with the + side matching.
4. Clip the body closed, fold the blade, and test the buttons from a few steps away.

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. The gap left by the metal key usually has a pry point. A slow twist with a thin flat tool (tape on the tip saves the plastic) opens the two halves.
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. Snap the halves back together, slide the metal key home, and press each button, then try the start button from the driver's seat.

Hyundai smart keys usually have a button that releases the mechanical key; a flat tool in the gap then opens 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.