The Flying Battery is a vessel that appears in the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics. It was a flying aircraft used by Dr. Eggman during one of his invasions of Angel Island. It served as both a battleship and research station.
Sonic the Hedgehog 3 & Knuckles
After Sonic and Tails made Dr. Eggman's Death Egg crash land on Angel Island for a second time, the two heroes invaded the Flying Battery during their mission to destroy the Death Egg for good. Knuckles later took a trip on the Flying Battery in pursuit of a fleeing Eggbot controlled by Dr. Julian Snively after multiple encounters on the island.
At the time of the Shattered World Crisis, the Flying Battery had long since crashed on Angel Island. There, it was identified by Relic the Pika as being equipped with advanced technology. After discovering signs of Eclipse the Darkling's presence on the island, she traveled to the Flying Battery alongside her assistant Fixit the Robot to analyze the evidence they had collected.