Power droid

Power droids were unsophisticated droids that acted as ambulatory batteries, recharging vehicles and machinery. They were equipped with a small, internal power generator, and several plug-in sockets.

Although they were extremely important to both military and civilian life, power droids were so commonly encountered in the galaxy that they often went unnoticed. The GNK-series by Industrial Automaton and the EG-series droid by Veril Line Systems were popular power droids. Both were commonly referred to as "gonks," after the low honking sound they emitted.

Non-canon appearances

 * LEGO Star Wars: The Force Awakens