Dirt Devil has developed a new energy efficient ENERGY STAR qualified line of cordless cleaning products. The Accucharge System protects batteries from degradation, meaning a longer battery life and effective runtime throughout its lifetime. Now charging twice as fast-- so you won"t have to wait as long between uses. Plus, special AccuCharge Circuitry constantly monitors the unit until the charge is complete and then reduces power to a trickle in order to complete and maintain the charge. This results in a reduction of energy consumption by 70%!