With Chernobylite Battery
While exploring the regions of Chernobylite, you might come across a safe in Kopachi, accessible through the sewer and bunker entrances in the lower-left corner of the map.
To open the safe, you’ll need assistance from the Locksmith, found in the top-right area of the map. However, he won’t help until you locate his brother, Athanasius, which isn’t possible until later in the campaign during the “Chain Reaction” mission.
During this mission, head to the upper floor of the prison complex, where you’ll discover a corpse. Examining it will reveal Athanasius's death. Return to the Locksmith, who will promise to unlock the safe the next time you visit. Inside the safe, you’ll find the Improved Flashlight perk.
If you have trouble finding the Locksmith at any point, he might be away. Simply complete a few missions or save/reload in the base before going to Kopachi.
