How to Replace the Key Fob Battery in a Hyundai IONIQ 6

1. Put the slim tool into the key hole (1) and pry open the rear cover of the smart key.
2. Remove the old battery.
3. Insert the new CR2450 battery, making sure its position is correct.
4. Reinstall the battery cover and the smart key cover.

• Battery Type: CR2450
• An improperly positioned battery may discharge the battery, causing smart key failure.
• A lithium button battery can cause severe or fatal injuries if swallowed; keep batteries out of reach of children.

Source: 2025 Hyundai IONIQ 6 owner's manual, PDF page 186. Steps are summarized in our own words (AI-assisted, checked against the cited pages 2026-10-18). Other model years can differ; your manual has the final word.