How can I find out how much current/power my phone can supply via USB-OTG? Is there a way to find out how much current or power a USB-OTG device can draw while connected to my phone? I'd be happy with something like:-


an online database like GSMArena with details for lots of phones
an app I can run on the phone to find it out e.g. from the USB host driver in the kernel
a file in /proc or /dev I can read (as root, if necessary)


I'd rather not have to test it with hardware by connecting a USB peripheral to it and increasing its current draw until it stops working.

The particular phone I'm interested in is a Nexus 5, but I'm really looking for an answer that's applicable to any phone (that supports USB-on-the-go).
I'm not sure this is entirely correct on Android, but on Linux, lsusb -v tells a lot about USB devices, including their maximum current output. If you can get usbutils on Android, that might tell you.