Lawrence Finch wrote:
And where did you hear that a Mac is only capable of supplying 1000 mA to an iPhone?
From the specs for my Macbook Air. My Macbook Pro doesn't specify the available current, but I just measured it with my iPhone 7 Plus, and it is delivering 1.5 amps, and briefly went up to 1.8 amps, so I accept your numbers. I don't know if can deliver that to more than one device, but I'll accept that it can. It definitely depends on the age of the Mac, however.
But the point wasn't what a Mac could supply, it is still about the fact that a device capable of supplying more than a device needs is not a problem and will not hurt the phone in any way, as long as it is an MFI certified power source. I routinely use a 4,000 Ma MFI certified Anker power adapter because it can charge up to 4 devices simultaneously.
Didn't you say that overnight you'll only use the 5W "ultracompact" adapter?
It's pretty well known that all the Macs with USB 3.X ports can supply 2100 mA directly to an iOS device. Now there are variations. I tried with my iPhone 7 and my iPad Mini 4 together directly to the two ports on my mid-2012 MBP. Depending on which one is plugged in first, once two devices are plugged in it reports 1500 mA to whichever one was plugged in first, then 1000 mA to the second device. So it's more than 2100 mA total, but not double the 2100 mA that it can send to one iOS device.
And yes I understand that a power supply is really just a voltage source where an iPhone's charging circuits will limit the incoming current. However, there are theoretically concerns that a higher maximum incoming current may slightly increase battery wear because of the heat. I don't think of it as a big deal; I'll trade the convenience of faster charging for the tiny increase in battery wear. If I need to use my iPhone and it's displaying less than 20% charge left, I'm not going to worry too much about it. For me that's part of the convenience of using the battery. I know there are theoretical concerns that it might slightly increase battery wear (compared to stopping it earlier), but the battery won't "turn into a pumpkin". I don't own an electronic device such that I'm babying it all the time. It's a tool with a replaceable battery.