The Brotherhood of Steel uses fusion batteries as a power source for some advanced equipment. The Warrior's squad was sent to the tribal village of Peoria, to retrieve fusion batteries from a pre-War storehouse over which the village was built. To complete the mission, three batteries must be found. However, by completing an additional objective, the Warrior can obtain a 4th battery, which can be researched by Brotherhood scribes.
Peoria bunker underground, northern part, in the blue locker in the room with several lockers and a safe (use the pass key to enter the room);
Peoria bunker underground, south-eastern part, found in the blue locker;
Peoria bunker underground, south-western part in yet another blue locker, in the room with Roachor;
(Optional) Peoria village, given by Chevron if Warrior manages to save villagers from being killed by laser turrets.