There are 4 ways to power your Beaglebone Black
- A USB port on a PC
- A 5VDC 1A power supply plugged into the DC connector.
- A power supply with a USB connector.
- Expansion connectors
The barrel power connector on the board is a 2.1 mm ID x 5.5 mm OD Center positive.
Below is from the Power sources section of the Beaglebone Black manual.
"The USB cable is shipped with each board. This port is limited to 500mA by the Power Management IC. It is possible to change the settings in the TPS65217C to increase this current, but only after the initial boot. And, at that point the PC most likely will complain, but you can also use a dual connector USB cable to the PC to get to 1A.
The power supply is not provided with the board but can be easily obtained from numerous sources. A 1A supply is sufficient to power the board, but if there is a cape plugged into the board or you have a power hungry device or hub plugged into the host port, then more current may needed from the DC supply.
Power routed to the board via the expansion header could be provided from power derived on a cape. The DC supply should be well regulated and 5V +/-.25V."