It has long been held by the tech-priests of the Adeptus Mechanicus, that at a certain point in a long-running appliances lifespan, it transcends it's earthly limits and gains the ability to tap into the limitless inter-stitial energy potential field that exists within the borders between the universes. They become as like unto a god, unconcerned by earthly matters like electricity. Deus In Machina. Unlike Ork "col' boxez" that continue to work in spite of their crude construction simply because they believe that they will. (or it could just be that they used really good design and insulation to minimize energy loss. It's really either or.)