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: Emergency Call (eCall) Unit
Components and components location Component The eCall unit for AVN is equipped in AVN head unit. Repair procedures Removal Carry out the Test Mode after: – Replacing the eCall unit – Replacing the Back-up Battery (BUB) – Replacing the eCall speaker and MIC – Replacing the eCall antenna and roof antenna • Be careful not to scratch the cluster fascia panel and related parts.Kia Stinger (CK) 2018-2023 Owner's Manual: Crankshaft Damper Pulley
Repair procedures Removal 1. Remove the engine room front under cover. (Refer to Engine and Transmission Assembly - "Engine Room Under Cover") 2. Remove the drive belt and water pump belt. (Refer to Drive Belt System - "Drive Belt") 3. Install the SST (0K231-2C100) on the crankshatf damper pulley, and then tighten the bolts (A).