Abstract: A method for communication between an external computer and a charging cable with an in-cable control box for charging battery-powered electric vehicles includes providing the charging cable with a data line for communication with the vehicle. A hardware interface between control box and computer allows access to the data line through the computer. Data for the control box is sent from the computer to the hardware interface, modulated by the hardware interface to the signal of the data line, and transmitted to the control box. Data for the computer is sent from the control box through the signal of the data line, converted by the hardware interface, and sent to the computer. The data is sent from control box to computer by modification of the pulse width of the signal of the data line and sent to the hardware interface, which forwards the data to the computer.