Originally Posted by prsterero
I wonder why the made it 1.8 if the n5 is only capable of 1.5 at most. Does the n7 have a higher charge capacity? Or maybe they're future proofing it for the new slew of nexus'
while those are possible minor considerations, the major one is for powering the wireless charger:
Conversion of 5VDC to a magnetic field, back into and inductive coil, into 5VDC again, comes with losses (in the form of heat). The Qi spec allows for the output of a inductive charger to meet but not exceed 1Amp. To do that, the input needs to be higher, about 1.5-2.0A. Ultimately what makes it to the battery will be less than 1A, probably 0.8-0.7A, so for the fastest charging, always use a cable.
That said, for overnight, Qi is great. Trickle charging is good for LiPo cells. (Conversely, heat is very bad for them, so the heat from the VDC->inductive->VDC->chemical energy isn't great. Life is about tradeoffs, haha.)