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: Cylinder Head Assembly
Components and components location Components 1. Cylinder head cover 2. Fuel pump bracket gasket 3. Cylinder head cover gasket 4. Positive Crankcase Ventilation (PCV) valve 5. Fuel pump bracket 6. Camshaft bearing cap 7. Camshaft front bearing cap 8. Intake camshaft 9. Intake E-CVVT assembly 10.Components and components location Components Repair procedures Removal 1. Turn ignition switch OFF and disconnect the negative (-) battery cable. 2. Remove the brake fluid from the master cylinder reservoir with a syringe. Do not spill brake fluid on the vehicle as it may damage the paint.