I wanted to see how much power the Anker Astro external battery draws when charging from the MacBook Pro (Retina, 15-inch, Late 2013) (right hand port next to the SD slot), but when listing the USB info in System Profiler, the battery doesn't show up as a device, it does receive some power though, but I thought to get more than the standard 500mA they would have to register and activate high-power mode (which I expected the battery to do).
Additionally it lists the SD card reader as requiring 896mA, but there's no card plugged in, seems odd that the empty reader would need that much power.
So I don't quite trust the output here, is there another way to list devices / get info from the hubs about how much power they are distributing?
$ system_profiler SPUSBDataType
USB:
USB 3.0 SuperSpeed Bus:
Host Controller Location: Built-in USB
Host Controller Driver: AppleUSBXHCI
PCI Device ID: 0x8c31
PCI Revision ID: 0x0005
PCI Vendor ID: 0x8086
Bus Number: 0x0a
Internal Memory Card Reader:
Product ID: 0x8406
Vendor ID: 0x05ac (Apple Inc.)
Version: 8.20
Serial Number: 000000000820
Speed: Up to 5 Gb/sec
Manufacturer: Apple
Location ID: 0x15400000 / 12
Current Available (mA): 900
Current Required (mA): 896
Built-In: Yes
USB 3.0 Hi-Speed Bus:
Host Controller Location: Built-in USB
Host Controller Driver: AppleUSBXHCI
PCI Device ID: 0x8c31
PCI Revision ID: 0x0005
PCI Vendor ID: 0x8086
Bus Number: 0x0a
Apple Internal Keyboard / Trackpad:
Product ID: 0x0262
Vendor ID: 0x05ac (Apple Inc.)
Version: 2.25
Speed: Up to 12 Mb/sec
Manufacturer: Apple Inc.
Location ID: 0x14c00000 / 3
Current Available (mA): 500
Current Required (mA): 40
Built-In: Yes
BRCM20702 Hub:
Product ID: 0x4500
Vendor ID: 0x0a5c (Broadcom Corp.)
Version: 1.00
Speed: Up to 12 Mb/sec
Manufacturer: Apple Inc.
Location ID: 0x14800000 / 2
Current Available (mA): 500
Current Required (mA): 94
Built-In: Yes
Bluetooth USB Host Controller:
Product ID: 0x8289
Vendor ID: 0x05ac (Apple Inc.)
Version: 1.03
Speed: Up to 12 Mb/sec
Manufacturer: Apple Inc.
Location ID: 0x14830000 / 4
Current Available (mA): 500
Current Required (mA): 0
Built-In: Yes
Best Answer
Standard USB output is 500mA.
If a device connected requests more it will be exceptionally given more, up to 1 Amp. (ie Card reader made that request).
If you device is not "identified", and did not make the request, it will get the 500mA.
Here is more information from Apple https://support.apple.com/en-us/HT204377
If you must know the real time current flow you would need one of the devices that do that Example: http://www.amazon.com/DROK-Extension-Multimeter-Connectors-Consumption/dp/B00S2IA3DG/ref=pd_sim_sbs_pc_7?ie=UTF8&refRID=179R1GBKK80252K5HW5V
or this one http://www.amazon.com/AboveTEK%C2%AE-USB-Voltage-Current-Multimeter/dp/B00ICR1UB6/ref=pd_sim_sbs_pc_3/175-5520415-2589050?ie=UTF8&refRID=179R1GBKK80252K5HW5V