The Smart USB charging cable is a charging cable with micro USB output (so for charging Android phone and most tablets) and integrated digital display.

The display informs you when the battery of the device which is being charged is full. This will be shown in two ways:

1) Display figures turns to Voltage instead of Ampere.

2) Ampere Blue LED indicator changes to Voltage indicator which illuminates green.

Because the display informs you that the battery is full, you can disconnect the charger from the mains to save energy, as many chargers use energy when they are connected but no longer charging.