iPhone - charge from iMac USB or 20W mains charger?

[slope]

Is one better than the other?

Both do it fast Of course charging from the iMac means the phone gets backed up too.

Tried searching for the power from the iMac USB 3.0 ports without joy.

The mains charger is a 20W folding pin Apple jobby with USB C to Lightning cable.

iPhone 13 Pro and 2019 27" iMac

[grams]

The dedicated USB C brick supports 9V charging which is faster.

AFAICT the USB C ports on Macs are 5V only, which limits them to 10-12 watts.

[PaulF]

But Lightning connections run at 5v don't they? So even if the brick can deliver 9v the phone will only take 5v? Certainly my iPad is no faster to charge from a USD C brick

[grams]

Lightning supports whatever Apple wants it to support.

iPhones from X/8 support fast charging (i.e higher voltages) over USB C:
https://support.apple.com/en-us/HT208137

[PaulF]

Lightning supports whatever Apple wants it to support.

iPhones from X/8 support fast charging (i.e higher voltages) over USB C:
https://support.apple.com/en-us/HT208137

thanks useful to know

[aidan.f]

If you are in no rush slow charging will be kinder to your battery. AFAIU an Apple phone is throwaway once the battery is bricked.

[grams]

Battery replacements are not completely unreasonably priced:
https://support.apple.com/en-gb/iphone/repair/service/battery-power

“Fast” charging on iPhones isn’t particularly aggressive. It’s only around 1C.

[ian]

I dunno, I went in to get mine replaced, and the woman used mental-telepathy to make me buy an entirely new phone.

[Jaded]

A tired battery can be replaced (not sure about a 'bricked' one?)

I've had a battery replaced (on a 6, I think). It worked well.  They did the screen at the same time as I dropped the phone when I got in the car to go to the Apple Store