Intentionally a friend of mine asked the question if a normal mobile phone powerbank can power the Raspberry Pi 3 and I had some laying around, so I tested it.
I used some powerbank with 5200mA (see Image above).
I put the Raspberry Pi on the 2,1A power supply and it ran for 4 hours and 48 minutes.
- USB 3.0 Segeate 1TB HDD
- USB Logitech WebCam
- Logitech Universal Receiver
- HDMI (1920×1080)