Pry open the key cover gently.
Replace the old battery with a new battery.

If the battery is assembled with incorrect polarity, it will discharge, rendering the key unusable.

WARNING

THIS PRODUCT CONTAINS A BUTTON BATTERY

If swallowed, a lithium button battery can cause severe or fatal injuries within 2 hours.

Keep batteries out of reach of children.

If you think batteries may have been swallowed or placed inside any part of the body, seek immediate medical attention.

NOTICE

The battery is CR2032 (3V).

CAUTION

The remote key or smart key is designed to give you years of trouble-free use, however it can malfunction if exposed to moisture or static electricity. If you are unsure how to use or replace the battery, Kia recommends to contact an authorised Kia dealer/service partner.
Using the wrong battery can cause the remote key or smart key to malfunction. Be sure to use the correct battery.
To avoid damaging the remote key or smart key, don't drop it, get it wet, or expose it to heat or sunlight.
An inappropriately disposed battery can be harmful to the environment and human health. Dispose the battery according to your local law(s) or regulation.