Can use ipad charger to charge iphone?

Michael Superczynski wrote:

You're new here so I'll cut you some slack.

Logic, rational thinking and the scientific method all mean nothing to the vast majority of posters in this thread.

Then can we just punch them?

John Galt wrote:

Welcome to Apple Support Communities Mr. Maxwell.

You will surely find its reflection on the human condition entertaining... or terrifying. I reached a conclusion on that subject long ago.

I can't be entertained as I read some of the posts and realize that the authors could be voting in our elections and home-schooling their children.

Yes, You can use the 2A iPad wall adapter to charge an iPhone. Using the 2A wall adapter will charge the iPhone faster than the 1A you were given when purchasing the iPhone.

It may just be my mind playing tricks on me, but the concept ive come up with in my head makes sense to me (I didn't research anything about electricity because im too lazy). I have noticed that the 2A wall adapter will charge the iPhone a lot faster, which makes sense and I understand. But the part I dont understand is that the battery life of the iPhone when using a 1A charger compared to charging with a 2A charger is much longer. (1A slower charge but longer life, 2A fast charging but it doesnt seem to last as long per 100% charge from 0)

If someone wants to test that for me as well or back me up/confirm it for me that would be great.

The decision is up to you though because it is 100% safe.

Noahwhite2014 wrote:

Yes, You can use the 2A iPad wall adapter to charge an iPhone. Using the 2A wall adapter will charge the iPhone faster than the 1A you were given when purchasing the iPhone.

Please provide data to support your contention.

Yes I did say I "didnt research" anything about electricity as in research anything now. But anyone who took ANY PHYSICS class had to have been through basic electrical concepts and vocabulary AT LEAST. These being : Ohms, resistance, voltage, AMPERE (Amps whatever you want to call it) and what they are and their relation to the others.

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Noahwhite2014 wrote:

Yes, You can use the 2A iPad wall adapter to charge an iPhone. Using the 2A wall adapter will charge the iPhone faster than the 1A you were given when purchasing the iPhone.

No it will not. this past week I did several controlled experiments, measuring the time to charge from 0% to 100% using each power source, and also measuring the charging current with this device while charging. The charging current with the 1 amp power source was 1.01 amps, tapering after 60% was reached linearly to zero at 100%.

The charging current with the 2.1 amp power source was 1.01 amps, tapering after 60% was reached linearly to zero at 100% (65% 0.94A, 70% 0.77A, 75% 0.6A, 90% 0.3A).

With both power sources, waking the phone increased the consumption to 1.1 amps. I could not get it higher than 1.1 amps with either. For the 1 amp power source this is no surprise, but I was a little surprised that the 2.1 amp power source was also limited to 1.1 amps, even running battery-intensive applications.

The power meter also measures voltage; the output voltage for each power source was 5.1 volts.

So the same amount of energy goes into the phone with either power source. Unless the laws of physics are being violated, with the same energy going into the phone from either power source it is not possible that one will charge faster (or slower) than the other.

And the actual measured charge times were the same also: 2 hours to 90%

Oh, just in case you think my 2.1 amp power source is defective, it charges my iPad at 2.05 amps.

The problem is that you don't have the remotest clue what the maximum ampere rating of the adaptor means or how regulated charging circuits (which are in the phone, not the adaptor) work.

As stated over and over and over and over and over and over and over and over and over and over and over again in this thread alone, as long as the ampere rating of the adaptor exceeds that maximum draw from the charging circuit (determined by the phone), additional increase in rating has absolutely no effect.

Noahwhite2014 wrote:

Yes I did say I "didnt research" anything about electricity as in research anything now. But anyone who took ANY PHYSICS class had to have been through basic electrical concepts and vocabulary AT LEAST. These being : Ohms, resistance, voltage, AMPERE (Amps whatever you want to call it) and what they are and their relation to the others.

Well, you clearly don't understand amperes. Your house probably has 150 amp service; that means that 150 amps comes into the house from the power company. So you had better not turn on any lights, because a 60 watt bulb is rated at only 0.5 amperes, so it will blow, and probably explode, instantly when that 150 amperes hits it.

As much as I'd like to agree with you on the speed of charging an iPhone, my results were showing differently.

Granted I did very simple tests, and the iPhone 4 and 4s are about the same age (when i bought them, one is not mine)

My charge times tended to vary between the two chargers with my iphone 4, 4s.

The iPhone 5 I used was a bit more controlled but in two separate time ranges 1:58:22 - 2:01:37 for the 1A adapter and 1:51:29 - 1:53:04 with the 2A adapter. I had all antennas turned off when i was doing these experiments. But with the 4 it would charge to 100% in just over an hour with the 2A charger (fastest time was 1:09:42) and the 1A charger would get me to 100 at about 1:43:XX almost every time (one outlyer at 1:42:03). The iPhone 4s was about the same but it wasnt tested as extensively nor used as much as the iPhone 4.

For a 21 page thread I will read the OP and hit reply without reading anything else. according to my tests, My iPhones are ALL broken internally due to the variance in charging times. Wonderful

Of course, a lot to learn which is why stray away from spending days on apple "support"

Instead, you spent many pointlessly wasted hours incorrectly "testing" iPhone charging times without understanding what you were doing, learning nothing, and helping no one. Wonderful!!

Oh come on Lawrence Finch - Give these guys a break huh?

Let's split this discussion a little shall we?

1 - Sure in a controlled test where all phone functions are switched off then regulating circuit will mean that both iPad and iPhone chargers charge the phone in the same time.

2 - But in real life most people charge their phones while they are switched on and the phone is doing some "stuff" that uses power - at that point the regulating circuit will let enough power through to both charge the battery maximally (according to the programming of said circuit) and provide power for the extra "stuff" ... The catch is that the iPhone chargers mostly can't supply max allowable charging current plus the extra little bit for the "stuff" the phone is doing while charging - Where as the iPad charger can.

So in practice the iPad charger will (for most people in most situations) charge the phone to full slightly quicker.

In practice that is not the case. I've also run that test. Using an iPad charger I tried loading down the phone with high usage functions (like phone calls, streaming music and downloads). No matter what load I put on the phone the measured current did not exceed 1.1 amps into the phone.

BTW, I was very surprised by that result. I assumed, as you did, that the iPad charger would supply additional current to run functions on the phone. The reason I suspect it doesn't is that the phone always draws power from the battery, even if connected to a power source. The phone does not bypass the battery if connected to the power source.

I find myself generally agreeing with you .. But .. Yes still that but from about ten pages ago - the only iPhone charger I have tested (mine) doesn't seem to deliver 1.1 amps .. The most I could coax out of it was 1.04 ... And yet the iPad charger will do the full 1.1.

I alluded to this ten pages or so ago and asked for someone to take me to task on it.

That difference equals a fraction quicker charge for iPad charger .. Sure only a minute or 2 .. But it's there.

"2 - But in real life most people charge their phones while they are switched on and the phone is doing some "stuff" that uses power - at that point the regulating circuit will let enough power through to both charge the battery maximally (according to the programming of said circuit) and provide power for the extra "stuff" ... The catch is that the iPhone chargers mostly can't supply max allowable charging current plus the extra little bit for the "stuff" the phone is doing while charging - Where as the iPad charger can.

So in practice the iPad charger will (for most people in most situations) charge the phone to full slightly quicker."

That sounds like a logical conclusion ** that is not the case. During my many tests I found then iPhones did not draw any more current from a 2 amp adapter than a 1 amp.

When charging I see a .93 amp draw charging within wifi/cellular on. With the screen on in see 1.03 amp. It's identical with both 1 amp and 2 amp charging adapters. The iphone only pulls .1 amp more in my tests.

I used this meter for my tests.

http://www.amazon.com/gp/aw/d/B00DAR4ITE

Bigapples wrote:

the only iPhone charger I have tested (mine) doesn't seem to deliver 1.1 amps .. The most I could coax out of it was 1.04 ... And yet the iPad charger will do the full 1.1.

Please see: http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html

The measured current output that he got was 1.79A from the 1A labelled iPhone charger. He has the expertise and measurement capability to convince me that his numbers are valid.