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Given a home made USB charger that simply provides 5 volts across the GND and VCC pins of a USB port, what should the default behavior be of any mobile device (mobile phone, tablet, iphone etc) plugged into that device. ('data +' and 'data -' left unconnected)
- completely ignore the device (i.e. not charge at all)
- attempt to trickle charge very slowly at low current
- attempt to charge at a current of no more than 500ma
- attempt to charge at a current exceeding 500ma
I have read this but am no wiser.