Energy absorber

An energy absorber is a vital component of Transformer anatomy that allows them the capacity to refuel, presumably with energon.

Fiction

Generation 1 cartoon continuity

Starscream "neglected" to equip his newly created Combaticons with energy absorbers in order to control them. He told them to obey him and they would capture and remove the energy absorbers from other Transformers and equip them in the Combaticons. Starscream's Brigade