Tesla device

I originally assumed the "Tesla device" was Elon Musk's battery technology in a box, which essentially would function as a giant UPS. This would be very useful, even if it just connected to mains power and separated electrically the house from shore power, as it would make brownouts and short duration blackouts a thing of the past. It would also make it easier to connect a backup generator, a solar array, a wind turbine, a hydroelectric turbine, and other items, because those can charge the batteries as they see fit, and not have an effect on what items are drawing from the battery bank.

Something from "Tesla" that gives unlimited energy like the Bedini motor (I will admit the Bedini motor is a showy way to desulfate batteries, but claims of it actually creating energy from electric fields is something can bite my bongos.)