iPad/iPhone charger if you only had one

LennyFL

macrumors member
Original poster
Mar 10, 2012
81
32
I travel a lot and don't like to carry duplicate items. So my question is can I use the iPhone or iPad charger on the other one?

Is the iPad charger to powerful for the iPhone or is the iPhone charger to weak for the iPad?

Lenny
 

xraytech

macrumors 68030
Mar 24, 2010
2,517
208
I travel a lot and don't like to carry duplicate items. So my question is can I use the iPhone or iPad charger on the other one?

Is the iPad charger to powerful for the iPhone or is the iPhone charger to weak for the iPad?

Lenny
iPad Charger will work just fine with both the iPhone and iPad.
 

ppilone

macrumors 6502
Jan 20, 2008
361
0
To add to the last post: you should not use your iPhone charger with your iPad.'

-- I'm wrong - see below.
 
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GraphicsGeek

macrumors 6502a
Sep 19, 2008
533
0
To add to the last post: you should not use your iPhone charger with your iPad.
Why not? You can use it but it'll take longer to charge the iPad since its only 5V. The iPad charger is 10V. Don't give wrong information. I've interchanged the chargers since iPad OG.
 

deeddawg

macrumors G3
Jun 14, 2010
8,298
2,175
US
The iPad charger is 10V. Don't give wrong information.
Actually, the iPad charger is 5.1V, you probably meant 10 Watt. :D

The voltage is 5.1V, and will output 2.1A according to the text written on it. iPhone charger states voltage is 5V, output 1A.

They're effectively interchangeable, iPad charger will charge the iPad faster.
 
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ppilone

macrumors 6502
Jan 20, 2008
361
0
Why not? You can use it but it'll take longer to charge the iPad since its only 5V. The iPad charger is 10V. Don't give wrong information. I've interchanged the chargers since iPad OG.
I was under the impression that because it's a lower power it could end up damaging the iPad battery?

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My fault - they're both 5V chargers. I'll correct my post.
 

profets

macrumors 601
Mar 18, 2009
4,446
4,158
Is there any worries for the reverse, using the iPad charger to charge the iPhone? I've done it a few times in the past, and it charged it to 100% insanely fast, but it also got quite hot while doing it.
 

rayyu882

macrumors member
Jan 18, 2010
92
0
Is there any worries for the reverse, using the iPad charger to charge the iPhone? I've done it a few times in the past, and it charged it to 100% insanely fast, but it also got quite hot while doing it.
Not sure why you're experiencing that, my iPhone 4s is charging now with the iPad charger and it's not hot at all.
 

Stealthipad

macrumors 68040
Apr 30, 2010
3,220
7
Is there any worries for the reverse, using the iPad charger to charge the iPhone? I've done it a few times in the past, and it charged it to 100% insanely fast, but it also got quite hot while doing it.
It should not get "quite hot". Warm is good but HOT?

I have used my iPad charger for my iPhones for years.

They have the same connector and Apple kind of thought this all out for us cause they know we will do it.
 

Julien

macrumors G4
Jun 30, 2007
11,152
3,856
Atlanta
I travel a lot and don't like to carry duplicate items. So my question is can I use the iPhone or iPad charger on the other one?

Is the iPad charger to powerful for the iPhone or is the iPhone charger to weak for the iPad?

Lenny
If you are a frequent traveler you should have something like this.
 

whtrbt7

macrumors 65816
Jun 8, 2011
1,008
72
USB 2.0 is power sensitive. It will automatically convert Amps and volts to the correct amount automatically. That said, if your adapter only supports so many Amps, you'll need a high amperage charger in order to downscale. I personally use a dual USB charger so I'm throwing about 4-6x the amount of amps at the USB connection so there is always adequate charge.
 

aka777

macrumors 6502a
Mar 13, 2012
818
373
Use the Ipad charger for both.

The iphone charger will charge the ipad but take a few extra hours minimum.
 

BigMcGuire

Contributor
Jan 10, 2012
4,679
5,724
California
I'm a software developer and I've taken an electrical engineering class in college but I have had people tell me both stories: "Oooh, having too many amps is a bad thing!" Then I've had others tell me "Not having enough will burn it out!" I've had people fighting in front of me trying to show how things work electronically.

I'm kinda fed up with it. I remember back in my Motorola Droid 1 days that having a 1A charger made the touch screen unusable (came with a 550mAh charger). I've read that my Kindle Touch can be damaged if I use a 1A charger.

But isn't the device drawing the power the one in charge of how much power gets to the device? So I could have a 500A charger plugged into an iPhone 4s and the iPhone will only draw 1A and be ok?
And the other way --- if I plug a 550mAh charger into an iPhone 4s, it will charge the iPhone albeit much slower than if I used the stock 1A charger, but it won't harm or burn out the battery, correct??? In fact, using a lower mAh charger can prolong the life of the battery from what I've read.

So which is it?
 

spiderman0616

macrumors 68040
Aug 1, 2010
3,465
3,699
I travel with my iPad charger and leave my iPhone charger at home connected to my charging station. The iPad charger works fine for both, but the iPhone charger sucks at charging the iPad.
 

profets

macrumors 601
Mar 18, 2009
4,446
4,158
Not sure why you're experiencing that, my iPhone 4s is charging now with the iPad charger and it's not hot at all.
It should not get "quite hot". Warm is good but HOT?

I have used my iPad charger for my iPhones for years.

They have the same connector and Apple kind of thought this all out for us cause they know we will do it.
Maybe I should have described it as warm/quite warm. It was with my iPhone 4 a year ago, using an iPhone 4S now.

Haven't had a need to use the iPad charger, but more I was wondering if there's any damage that can happen when charging with with higher output of the 10W charger.
 

aka777

macrumors 6502a
Mar 13, 2012
818
373
So which is it?
Here it is, as long as the voltage is similar, the amps do not matter. For example, if a device accepts 5v and you feed it 8v - it's done.

When it comes to amps having the minimum and up is recommended. Your device will typically only draw the amps it needs.

So if you use the ipad charger (~2.1amps) on the iphone (~1amp) - it's fine, as the iphone will only draw the 1 amp it needs.

Think of it in terms of computer power supplies. A computer that requires 500 watts of power for every peripheral to run does fine using a 750W power supply. Watts = Amps x Volts

The #1 reason they supply the appropriate amperage power adapter is to improve efficiency and reduce size. A 1 amp charger will be smaller and more efficient than supplying a 2 amp for a device than only needs 1 amp.
 

BigMcGuire

Contributor
Jan 10, 2012
4,679
5,724
California
Here it is, as long as the voltage is similar, the amps do not matter. For example, if a device accepts 5v and you feed it 8v - it's done.

When it comes to amps having the minimum and up is recommended. Your device will typically only draw the amps it needs.

So if you use the ipad charger (~2.1amps) on the iphone (~1amp) - it's fine, as the iphone will only draw the 1 amp it needs.

Think of it in terms of computer power supplies. A computer that requires 500 watts of power for every peripheral to run do fine using a 750W power supply. Watts = Amps x Volts

The #1 reason they supply the appropriate amperage power adapter is to improve efficiency and reduce size. A 1 amp charger will be smaller and more efficient than supplying a 2 amp for a device than only needs 1 amp.
Many thanks for taking the time to type that out. I was sure Amps didn't matter but forgot what did matter (volts). Wish I had eidetic memory.
 

whtrbt7

macrumors 65816
Jun 8, 2011
1,008
72
Higher amperage is allowed when charging via USB 2.0. The reason for this is due to the way voltage flows through USB 2.0. If your amperage is too low, the device will do 1 of 2 things. Your device may not charge at all because there is not enough amperage to matter to the connection. Your device may drain power because the connection is going the other way. USB 2.0 works like this because it's not like how older 120V vs 240V converters used to work. I've attached the website with the formulas for calculating each side of the connection. You also need to think about the battery inside the device and how it works. Overall, higher amperage devices will work compared to low amperage devices. Also, higher amperage devices typically cost more than low amperage.

http://www.simetric.co.uk/si_watts.htm
 

aka777

macrumors 6502a
Mar 13, 2012
818
373
Many thanks for taking the time to type that out. I was sure Amps didn't matter but forgot what did matter (volts). Wish I had eidetic memory.
No problem.

I knew those electronics classes would come in handy one day.
 

Stealthipad

macrumors 68040
Apr 30, 2010
3,220
7
Maybe I should have described it as warm/quite warm. It was with my iPhone 4 a year ago, using an iPhone 4S now.

Haven't had a need to use the iPad charger, but more I was wondering if there's any damage that can happen when charging with with higher output of the 10W charger.
It will not harm you iPhone to use the iPad charger.
 

profets

macrumors 601
Mar 18, 2009
4,446
4,158
Here it is, as long as the voltage is similar, the amps do not matter. For example, if a device accepts 5v and you feed it 8v - it's done.

When it comes to amps having the minimum and up is recommended. Your device will typically only draw the amps it needs.

So if you use the ipad charger (~2.1amps) on the iphone (~1amp) - it's fine, as the iphone will only draw the 1 amp it needs.

Think of it in terms of computer power supplies. A computer that requires 500 watts of power for every peripheral to run does fine using a 750W power supply. Watts = Amps x Volts

The #1 reason they supply the appropriate amperage power adapter is to improve efficiency and reduce size. A 1 amp charger will be smaller and more efficient than supplying a 2 amp for a device than only needs 1 amp.
Thanks, makes sense.

In theory then, using the 2.1 amp charger and the phone drawing 1 amp, it should charge in the same amount of time as if it was using a 1 amp charger right? I only ask as it seems like the iPhone when used with the 2.1 amp charger charges much faster. Maybe it's capable of drawing more than 1 amp?

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Apple mentions that it is ok:

http://support.apple.com/kb/HT4327

The iPad USB Power Adapter is a 10W charger. While designed for use with the iPad, you can use the iPad 10W USB Power Adapter to charge all iPhone and iPod models by connecting them using a Dock Connector to USB cable.
 

Leonard1818

macrumors 68020
Nov 15, 2011
2,459
393
Thanks for all of the info everyone. I read about charging the iPad on apples website and it sounds like I can still use an older iPhone cable plugged into a computer using a newer usb 2.0 connection to charge the iPad.

Anyone use older iPhone or iPod cables for the iPad and a computer?
 

aka777

macrumors 6502a
Mar 13, 2012
818
373
Thanks, makes sense.

In theory then, using the 2.1 amp charger and the phone drawing 1 amp, it should charge in the same amount of time as if it was using a 1 amp charger right? I only ask as it seems like the iPhone when used with the 2.1 amp charger charges much faster. Maybe it's capable of drawing more than 1
Charging typically takes the same amount of time when the minimum amp is meet. It only increases dramatically when the amp is lower. A device can sometimes draw more power to charge a little quicker, however, charging is often limited by properties (and safety) of the battery itself.

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Thanks for all of the info everyone. I read about charging the iPad on apples website and it sounds like I can still use an older iPhone cable plugged into a computer using a newer usb 2.0 connection to charge the iPad.

Anyone use older iPhone or iPod cables for the iPad and a computer?
Most computer USB ports I have used only deliver 500mA max, which is way bellow the 2.1A required by an iPad. That would take 8+ hours to charge the original ipad at that rate. My original ipad stated that it was not charging whenever I plugged it into a PC. The latest ipad's battery is double the capacity.
 

Leonard1818

macrumors 68020
Nov 15, 2011
2,459
393
Most computer USB ports I have used only deliver 500mA max, which is way bellow the 2.1A required by an iPad. That would take 8+ hours to charge the original ipad at that rate. My original ipad stated that it was not charging whenever I plugged it into a PC. The latest ipad's battery is double the capacity.
thanks for your reply. Looks like I'll be on the hunt for another ipad wall charger for my wife. 1 at home, 1 at work!