In the D’Agostino exhibit, pure AC power was fed to the Progressive monoblocks by a Stromtank independent power source ($30,000): a 276-lb enclosure in which a 16-cell Lithium phosphate battery pack stores up to 4000W, ultimately to be converted to pure-sinewave AC. Four hospital-grade AC outlets are provided for source components and an additional two outlets serve to support power amplifiers. Stromtank claims that their power source can provide between 5 and 8 hours of pure AC power between charges.