Electrical connectors can transmit data, signals, and/or power to and between electrical devices, such as computing devices. The computing devices may include portable computing devices such as laptop or notebook computers, tablets, netbooks, or smartphones. The computing devices may include desktop computers. In some cases, an external power source can provide power to a computing device. Cables can include connectors on both ends that can connect power and/or data between the electrical devices and between the external power source and the computing device.
In some cases, the external power supply can provide power to the computing device at one of many voltage levels (values). The computing device, using a communication protocol associated with the connectors, can provide data to the external power supply identifying a voltage for the power the external power supply can provide to the computing device.