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: High Pressure Fuel Pump
Repair procedures Removal 1. Release the residual pressure in fuel line. (Refer to the Fuel Delivery System - "Release Residual Pressure in Fuel Line") 2. Switch "OFF" the ignition and disconnect the negative (-) battery terminal. 3. Disconnect the fuel pressure control valve connector (B) and the fuel feed tube quick-connector (A).Description and operation Description 1. The ESP OFF switch is for the user to turn off the ESP system. 2. The ESP OFF lamp is on when ESP OFF switch is engaged. Repair procedures Removal 1. Turn ignition switch OFF and disconnect the negative (-) battery cable.