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: Wireless Power Charger (WPC) System
Specification Specifications Item Specification Rated voltage DC 12 V Operating voltage DC 9.0 - 16.0 Operating temperature -86 - 167°F (-30 - 75°C) Dark current Max. 1 mA Output power 5 W Output frequency 110 ± 5 kHz Components and positions Components 1.Opening the hood 1. Pull the release lever to unlatch the hood. The hood should pop open slightly. Only open the hood with the vehicle on a flat surface, engine is turned off, shift lever placed in P (Park) position and setting the parking brake. 2. Go to the front of the vehicle, raise the hood slightly, push the secondary latch (1) left side of the hood center and lift the hood (2).