Replace the Key Fob Battery

Last updated: June 12, 2026

If the remote on your Hyundai Kona Mk1 (OS, 2017–2023) has become weak — you have to stand close to lock or unlock, or a low-battery warning has appeared — the fob’s coin cell needs replacing. The Kona uses a CR2032 cell in both the standard remote and the keyless smart key. This guide covers both styles. It takes a couple of minutes with a small screwdriver.

Which Key Do You Have?

• Type 1 — standard remote key: a fob you split open with a screwdriver. Cell sits positive side up.
• Type 2 — keyless smart key: push-button start cars; has a pull-out mechanical key. Cell sits positive side down.

Both take a CR2032 3 V lithium coin cell.

Type 1 — Standard Remote (CR2032, positive up)

1. Find the seam in the fob case and insert a flat-bladed screwdriver to gently separate the two halves.
2. Remove the button-cell cover and lift out the old CR2032 cell.
3. Fit the new cell with the positive (+) side facing up.
4. Click the two halves back together.
5. Check the remote locks and unlocks the car.

Type 2 — Keyless Smart Key (CR2032, positive down)

1. Press the small release button and pull out the mechanical (emergency) key.
2. Using the slot the key leaves, gently separate the case halves.
3. Remove the old cell and fit the new CR2032 with the positive (+) side facing down (note: opposite to the standard remote).
4. Reassemble the case and refit the mechanical key.
5. Check the smart entry and start work normally.

Does It Need Programming?

No — replacing the coin cell does not affect the fob’s pairing, so the key keeps working immediately. A brand-new or replacement key, however, can only be ordered from a dealer and programmed with a diagnostic tool — that part is not owner-doable.

Frequently Asked Questions

What battery does the Kona key take?

A single CR2032 3 V lithium coin cell in both the standard remote and the smart key. Mind the orientation — positive up in the standard remote, positive down in the smart key.

Will the car still start if the smart-key battery dies?

Yes. Hold the fob against the start button (Hyundai marks the spot) to start using the backup transponder. The mechanical key in the fob unlocks the door.

My remote still won’t work with a fresh cell — now what?

Re-open it and check the cell orientation and that the contacts are clean. If it’s still dead, the fob may have an internal fault and need replacing and programming by a dealer.

Can I program a spare key myself?

No — Hyundai key programming needs the dealer diagnostic tool. Only the battery swap is owner-doable.

To clear a service reminder after maintenance, see our Hyundai Kona service indicator reset guide. For warning lights, look up the code on autodtcs.com.