These instructions apply to the Hyundai i30 Mk3 (PD) 2017-Present.
For other models, please choose your vehicle here.
If the remote on your Hyundai i30 Mk3 (PD, 2017–present) has gone weak — you have to be close to lock or unlock, or a “key battery low” message has shown — the fob’s coin cell needs renewing. The i30 key uses a CR2032 cell and opens with the help of the emergency key blade. This guide shows how, with no programming required.
What You Need
- One fresh CR2032 3 V lithium coin cell.
- The fob’s built-in metal key blade, plus a small flat screwdriver to release the cover.
How to Replace the i30 Mk3 Key Battery
- Pull out the mechanical key blade — slide the release latch and withdraw it.
- Using the gap the blade leaves (or the seam), prise the case apart gently with a small flat screwdriver to remove the button-cell cover.
- Lift out the old CR2032 cell, noting its orientation.
- Fit the new cell with the positive (+) side facing up (same way as the old one).
- Click the case back together and slide the key blade home.
- Test lock/unlock and keyless entry from a normal distance.
Does It Need Programming?
No — renewing the coin cell does not affect the fob’s pairing, so the smart key keeps working straight away. A lost or broken key can only be ordered and coded by a Hyundai dealer — that part isn’t owner-doable.
If It Still Won’t Respond
Re-open the fob and check the cell sits with the right side up and the contacts are clean. If keyless entry is slow to pick up, hold the fob against the start button once (the i30 marks the backup spot) to start, then it re-syncs.
Frequently Asked Questions
What battery does the i30 Mk3 key take?
A single CR2032 3 V lithium coin cell.
Will the car still start if the key battery is flat?
Yes. Hold the smart key against the start/stop button (Hyundai marks the spot) to start using the backup transponder. The key blade unlocks the driver’s door.
Which way up does the cell go?
Positive (+) side facing up, matching the cell you removed.
Can I program a spare key myself?
No — Hyundai key coding needs the dealer system. Only the battery swap is owner-doable.
To clear a service reminder after maintenance, see our i30 Mk3 service indicator reset guide. For warning lights, look up the code on autodtcs.com.
Independent guide — not affiliated with Hyundai. Always follow your official service manual and safety precautions. Read our full disclaimer.