Teen Titans S01 E05 The Sum of His Parts

"When there's trouble, you know who to call."

While playing in the park Cyborg suddenly shuts down. After rebooting he tells the other Titans that his batteries are dying. During a battle with Mumbo, Cyborg's emergency batteries die and he is lost. The Titans believe Mumbo to have kidnapped him, but he has instead been found by a strange man called Fixit.