Cordless convenience with an Energy Star rating! The AccuCharge™ system charges twice as fast so you can be ready for any quick pickup with 15.6 volts of cordless cleaning power. When the unit is charging, the AccuCharge™ circuitry constantly monitors the battery. Once the battery is charged, power is reduced to a trickle to maintain the battery without drawing extra power. This remarkable system reduces energy consumption by 70% and extends the life of the battery.