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30W USB-C charger vs 18W USB-C charger in "fast charging" times

Luba

macrumors 65816
Original poster
Apr 22, 2009
1,413
227
Anybody have the 30W USB-C charger and the 18W USB-C charger, and have an idea how much faster the 30W is compared to the 18W in fast charging an iPhone Xs?
 

scotsmandc

macrumors 6502
Sep 26, 2015
308
161
No difference. I believe the phone is capped at 12w charging so it doesn't matter if you have a higher watt charger.
 
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cappo3

macrumors regular
Dec 3, 2014
171
58
No difference. I believe the phone is capped at 12w charging so it doesn't matter if you have a higher watt charger.
That can't be right. If it was true, you'd reach maximum charging rate with a 12W iPad charger. But we know that iPhones can "fast-charge" now.
 
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ZStech

Suspended
Feb 3, 2019
150
31
That can't be right. If it was true, you'd reach maximum charging rate with a 12W iPad charger. But we know that iPhones can "fast-charge" now.
I agree with this post, it can't be truth that there is no difference.
 
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bigjnyc

macrumors 604
Apr 10, 2008
6,566
3,881
The difference between the 12W and the 18W is not really that big. But I am surprised to see that there is no difference above 18W.....
 
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Alameda

macrumors 6502a
Jun 22, 2012
624
111
The difference between the 12W and the 18W is not really that big. But I am surprised to see that there is no difference above 18W.....
The phone will only draw so much current. Applying too much charge current cab overheat the battery and even cause a fire. It also means different charging circuitry to handle the higher current. Assuming that’s mitigated, charging a LiIon battery more slowly will increase its longevity.
 
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BugeyeSTI

macrumors 68040
Aug 19, 2017
3,670
2,545
Arizona
That’s one of the reasons I never purchased the 18w charger. 12w iPad charger is plenty fast and it came with my Air2 so why spend the $30 for slightly faster charge times
 
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TheIntruder

macrumors 65816
Jul 2, 2008
1,297
827
Macworld's testing also reinforces the notion that a wired 12W adapter is the sweet spot that best balances cost/performance when charging a phone. As well as flexibility, given the ubiquity of USB-A/Lightning cables.

For something like an iPad, whose batteries can be 2-3x the capacity of those in iPhones, the gains will be more than incremental, and justify the additional outlay for a higher-wattage PD setup.
 
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MrMister111

macrumors 68040
Jan 28, 2009
3,126
214
UK
That’s one of the reasons I never purchased the 18w charger. 12w iPad charger is plenty fast and it came with my Air2 so why spend the $30 for slightly faster charge times

I bought the 18W as can also use for my iPad pro as does help a lot on charging times for that, and also as it has the folding pins here in UK so makes it a lot more compact than the 12W iPad one as in UK the pins are big, folding makes it much better.


 
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KOTN91

macrumors regular
Nov 23, 2017
215
147
I simply cannot fathom why anybody would actually want the type of port to change again, lol.

The future is completely portless and real wireless charging. That’s 5-10 years away though and until then the iPhone should continue to use lightning
 
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MrMister111

macrumors 68040
Jan 28, 2009
3,126
214
UK
Can yu tell how much is limit for new ipad air 3
I mean what is it caped at ??
Can 30w work for it or 18w will be enough ??

I believe it is 18W max anyway for new iOS devices. I think it's the actual device that limits the power input, so it will only draw what needs, so you can use the 30W fine.

Just noticed it's actually sold on (UK) Apple store now as well, so presume Apple tested it and happy! States can charge an iPhone 8 and later (ie fast charge compatible) 50% in 30mins.
 
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Aditya rathee

macrumors regular
May 1, 2019
166
40
India
I believe it is 18W max anyway for new iOS devices. I think it's the actual device that limits the power input, so it will only draw what needs, so you can use the 30W fine.

Just noticed it's actually sold on (UK) Apple store now as well, so presume Apple tested it and happy! States can charge an iPhone 8 and later (ie fast charge compatible) 50% in 30mins.
Yeah i agree
But few mins back i saw a video on youtube in which a person was charging its iphone xs max with 87w usb c charger and it charged full in around 1 hr and 37 mins
So i guess my ipad can draw more power than an iphone xs max
Right ?
 
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Sparxxx

macrumors regular
Jul 29, 2009
244
51
All Iphones which support fast charge (from Iphone 8 and later) are capped at 18W
All Ipads who support fast charge (I think it's only the Pro Versions using USB-C) are caped at 29W.
You can safely use 30W or even 60W... the device will "pull" only what it "needs". This is valid untill 50%, after that the wattage will drop.
 
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