Fusion furnace

The fusion furnace, or power unit, was a small, easily transported power generator used to recharge energy cells, such as those found in droids, vehicles, weapons, and powered armor. Additionally, fusion furnaces generated heat and light while active. Some domestic items were fitted with fusion furnaces, eliminating the need for energy cells.

Industrial fusion furnaces were used in GRZ-6B wrecker droids; these furnaces were hot enough to melt the toughest of metals and materials - powerful magnetic fields would then separate the plasma into component elements, which would then be recombined and stored for later retrieval.

R2-D2 recharged himself using a fusion furnace at the Lars homestead after being purchased by Owen Lars, and later Luke Skywalker brought a fusion furnace with him to Dagobah to recharge R2-D2.

Children of Tatooine sometimes told stories of dragons which lived inside fusion furnaces. Larger cousins of these creatures, known as sun-dragons, were prophesied to live inside stars.

Text and facts from the “Fusion furnace/Legends” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.