Hyundai Sonata Hybrid key fob battery
2 of the 12 model years listed for the Hyundai Sonata Hybrid have a proven battery. The most common answer is CR2032. Rows below run oldest to newest; a year can appear twice when the car came with more than one kind of key.
- 2011-2014Unknown
Not confirmed yet
- 2015Smart key
CR2032
FCC ID SY5HMFNA04Two sites agree: uhs-hardware.com and bestkeysupply.com (checked Nov 1, 2026)
Find CR2032 on Amazon - 2016Unknown
Not confirmed yet
- 2018-2019Unknown
Not confirmed yet
- 2020Smart key
CR2032
Two sites agree: manua.ls and energizer.com (checked Nov 2, 2026)
Find CR2032 on Amazon - 2021-2023Smart key
Not confirmed yet
Changing the battery
Smart key (push-button start)
- Start by freeing the hidden metal key: there is a latch or slide on the case, and the blade comes out once it moves.
- 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.
- 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.
- Close the case until it clicks all the way round, put the metal key back, then try the buttons and a push-button start.
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.
If a child might have swallowed a coin cell, treat it as an emergency and get to a hospital right away.