Abstract: A single data and power interface, or combination of several such integral data and power interfaces, are used to manage power across one or more batteries and external input power sources. In one embodiment, an interface may be capable of sinking power in order to charge a battery, and then source power from the battery through the same interface. In another embodiment, multiple devices having integrated data and power interfaces are used to manage one or more battery units for emergency power or for mobile operation where the interface may be connected to a power source for charging, but may also be used to source power from the battery to operate another device during mobile operation.