Theystilluse a smallamountofpower, andthesamegoesforyourphonechargerleftinthesockettochargeyourphone.
Thisblocktransformedthe A C oralternatingcurrentto D C, alsoknownasdirectcurrent, aswellaslowersthevoltagesoasnottofryyourdevice.
Whenthecharterispluggedinbutnotconnectedtoyourphone, it's stilltransformsthecurrentinvoltage, consuming a minusculeamountofenergyover a year, thoughitmightreallyaddup.