An electrical appliance, such as a shredder, having low standby power consumption is provided. A power isolation circuit is positioned to electrically disconnect electronic components of the shredder from the shredder's primary power source. An auxiliary power source may generate or store power for powering electronic components, such as sensors or processors, while the primary power source is disconnected. A power isolation controller may use a timer, light detector, or user interaction sensors to determine whether to reconnect the primary power source to the electronic components.