Oil batterys were giant batterys filled with petroleum that were being used to store & use oil for energy. Six were created in the United States, five being placed in various locations lining the Eastern coast & one in a specific location off the coast of California & Oregon, all being placed in the hearts of drilling platforms meant for mining underwater oil. The batterys were relocated into a pentagon array around the Great Lakes Citadel after Operation Slick Metal. During the mission, the battery in the Pacific exploded when a large battle occurred on the platform it sat on. This battle signifyed the beginning of the Imperial Army.