Contents:

The battery is in the trunk under the compartment cover.
When replacing the battery, disconnect the negative (-) cable (1) and remove the positive (+) battery fuse box (2).
Remove the battery mounting bracket (3).
WARNING - Touching metal surfaces in the trunk under the compartment cover

Do not touch metal surfaces in the trunk under the compartment cover while the engine is operating or hot. Doing so could result in serious personal injury. Turn the engine off and wait until it cools down or wear gloves to replace the battery from the luggage room.
Your vehicle has a maintenance-free, calcium-based battery.
When recharging the battery, observe the following precautions:
Reset items
Items should be reset after the battery has been discharged or the battery has been disconnected.
Kia Stinger (CK) 2018-2023 Owner's Manual: Smart Key Unit
Components and components location Components Connector Pin Information No. Connector A Connector B Connector C 1 - B-CAN (Low) Front wiper low bus switch_Input 2 Mirror power_Input B-CAN (High) Ground (Power) 3 P-CAN (Low) PDW-F_Power_Output Battery (Power)Kia Stinger (CK) 2018-2023 Owner's Manual: Console ON/OFF Actuator
Repair procedures Inspection 1. Turn the ignition switch OFF. 2. Disconnect the mode control actuator connector. 3. Verify that the mode control actuator operates to the defrost mode when 12V is connected to terminal 3 and ground to terminal 7. Verify that the mode control actuator operates to the vent mode when connected in reverse.