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: Specifications
Service data Service data Automatic Transmission Item Specification Transmission model A8LR1-1 Drive type 2WD / AWD Engine THETA ll 2.0 T-GDI (Gasoline) Clutch type Torque converter Oil pump type Internal gear Shift Lever type *SBW / *SBC Component elementsKia Stinger (CK) 2018-2023 Owner's Manual: Front Stabilizer Bar
Repair procedures Removal 1. Remove wheel nuts, front wheel and tire (A) from hub. Tightening torque: 107.9 - 127.5 N·m (11.0 - 13.0 kgf·m, 79.6 - 94.0 lb·ft) Be careful not to damage the wheel bolts when removing the wheel and tire (A).