Sick of Apple chargers? Solution: SupperCharger+, the Next Generation

[SharpEars]

... so some good measurements on the iPhone would probably be enough to put to rest all the speculation.

Unless the iPad attempts to draw more current than the iPhone (definitely true), which the charging circuitry dropout + supply sag can't sustain (unknown).

Also, we haven't really accounted for where all this extra current is going, have we? Perhaps only of academic interest, but interesting to consider nevertheless.

Well, assuming all of the charge amounts were equal as the charge gauge on my phone seemed to indicate, it's clear that the extra current is being converted into heat. The big question is by what? Maybe if I take the phone apart and start measuring around the circuit in/on the battery I can figure this out.

[suicidaleggroll]

Maybe the dc/dc converter is highly optimized for the expected voltage level of a stable 5.0v source and a 1m ~24 awg wire at the expected current draw?  So it's designed so the efficiency is optimal with an actual input voltage of ~4.75v, and when you try and feed it 5.3v the efficiency drops off?  I wouldn't expect it to drop off so quickly though.

[Niklas]

Charging 20 minutes from empty battery... Did you measure the actual current during the entire charge time of 20 minutes? An empty battery is typically charged with a lower current, maybe 10% of the fast charge current, until the cell voltage reaches a threshold to allow fast charging.

[SharpEars]

Charging 20 minutes from empty battery... Did you measure the actual current during the entire charge time of 20 minutes? An empty battery is typically charged with a lower current, maybe 10% of the fast charge current, until the cell voltage reaches a threshold to allow fast charging.

There was a slight increase in charging current start to finish, but nothing significant.