Patent ID: 8214545

Claim:
A multi-functional Universal Serial Bus (USB) system comprising: a first USB apparatus exhibiting multi-functionality, having a USB host port, a USB client port, audio/video (A/V) input and output interfaces, a memory module, electronic circuitry; and a processing engine controlling and managing the USB host port for data storage and transfer to external USB client devices, USB client port for data exchange with a computer and as a power receptacle, A/V input/output, memory module for internal data storage, and electronic circuitry of the USB apparatus; a second USB apparatus having the form of a USB cap housing a battery module and a USB host port connector and functioning as a power source; wherein power is provided by the USB cap through its USB host connector pins by coupling both structurally and electrically with the first USB apparatus through its USB client port; and wherein the USB cap continuously monitors the level of output voltage of the rechargeable battery and indicates a low voltage warning and signals the low voltage warning to the first USB apparatus, when the battery voltage falls below a predetermined threshold.