Can use ipad charger to charge iphone?

I've been charging my iPhone 3G with the iPad charger for 1 1/2 years. It's working fine and charges the iPhone faster.

I did notice a small decrease in iPhone's battery performance, but I think that's just down to the fact that the phone is now 3 years old.

If 'clearly this IS harmful' were true, then why have I never had any problems charging my iPhone 3G, 3GS, 4, 4S using an iPad charger.

Apple's power supplies are intelligent and will not supply more current than the device can handle. In your case, I'd venture something else is causing the problem.

I can to have a look to answer the same question. One of th later google entries was this http://store.apple.com/uk/product/MC359B/A it talks about the iPad charger charging the iPhone and ups touch as well

Hope this hels

So, it won't work on the "old" 3GS?

You can use an iPad charger with any iPhone. Or any device that can be charged from USB, for that matter. One of the few things the industry has done right is standardize the power supplied by a USB port. An iPad will need a higher current than an iPhone, so you can't charge an iPad effectively from an iPhone charger, but the other way works.

Yes, you can charge your iPhone with the iPad adapter. There's a lot of confusion about this, partly b/c Apple is mum about even basic tech specs. However, the basic issue is that the 10W spec (pretty much the only detail you can find on Apple's website) is the power output, not the voltage (as some people on this thread have said). Presumably, this is significantly higher than the power output available from the iPhone power adapter, but that doesn't matter. It "wattage" is the power output *available*. The iPhone will simply draw less current than the iPad.

Also, it says that it is compatible right on the Apple website. Quote from iPad charger website:

"Featuring a compact design, this power adapter offers fast, efficient charging and includes a 6-foot-long power cord so you can plug it in under a desk or behind the couch. It also charges iPhone and all iPod models with a dock connector."

I just recently got an iPad and have the iPhone 4, iPhone 4S, iTouch, Ipod, basically I have everything Apple makes. I can see that a lot of people are confused about chargers due to them showing watts, volts, & amps and since I have a very extensive background in electronics I will clarify all this in this post.

Chargers:

PC USB 5 Volts, .5 Amps 2.5 watts

iPhone Charger 5 Volts 1.0 Amps 5 watts

iPad Charger 5.1 Volts 2.1 Amps 10 watts

Will they all charge an iPad even when your PC shows "Not Charging" YES your PC USB will charge your iPad, but very, very slowly because it is 1/4th of what an iPad charger is so it will take 4 times longer than an iPad charger (BUT YOUR SCREEN MUST BE OFF). To test that plug your iPad into your PC USB charger before you go to bed and write down what the battery percentage is and in the morning you will see it went up. Not much, but it will go up some. Reason it says "Not Charging" when you are looking at the screen when plugged into your PC is the USB is basically powering up your screen and doing nothing for the battery.

If you use an iPhone charger it will show the iPad is charging, now look above at the numbers and you see that it is about 1/2 of what the iPad charger is so it will take twice as long to charge up your iPad using an iPhone charger. Below these are totally hypothetical numbers and not realistical and I am using them to keep it simple and understandable.

If it takes your iPad charger 5 hours to charge up your iPad with the iPhone charger it will take 10 hours to charge it because it is about 1/2 the watts and amps. Make sense? Its basically just doing the math. I have not tried to do a full charge using a USB Port on my PC, but I believe like I said doing the math it will take 4 times longer because the USB port is 1/4 the output of the iPad charger and 1/2 the output power of the iPhone charger. But remember if you have your iPad screen on the USB on your PC is just powering up your screen and doing nothing for charging the battery. To test that I would have to take a guess and say let your iPad run down to say 20% or so, turn it OFF, plug it into your USB Port and power it up after I would say at least 12 to 16 hours to see where it is at. It will charge the battery I know that for sure, but it is going to take 4 times longer.

I hope this clarifies things up for everyone on this because it is all just math with the output because they all produce 5 volts only difference is Amps and Watts and the equations for that is Volts x Amps = Watts. Apple gives you the 2.1 Amp 10 Watt charger so it won't take a day to charge your iPad due to the battery being much bigger.

Most USB Hubs produce the .5 Amps even though they have an external power supply you plug into the wall. Their are some USB Hubs that have usually 1 port that will produce the 10 watts 2.1 amps, but it will just be out of one port on the hub, so if you buy one read the specifications carefully. Car chargers are pretty much the same, so read before you purchase.

Here is the name of a USB Hub that has ONE fast charge port they call it that is the same as the iPad Charger: Symba 7 Port USB 3.0/2.0 Hub with One Fast Charging USB 2.0 Port (SD-HUB20102) if you want to charger fast and sync your iPad on your PC

If you are looking for a Car Charger that is 2.1 amps just like the Apple Charger I got a Satechi 2412ST and what is really nice about it is that it is pretty much flush when plugged in, meaning you don't have this charger sticking out of your accessory socket it is flush which is really nice if you have a cove that needs to close you can leave this in...

I know this is long, but I hope all this helps and clears things up for everyone and if you buy any USB Hubs or Car Chargers for your iPad read carefully that it produces 2.1 Amps to get the fastest charge or if you don't mind it charging slower (1/2 as fast) you can get a 1.0 Amp one.

Merlin,

Thank you for your excellent analysis. Would it be OK with you if I post this as a forum tip (giving you credit, of course).

Sure go ahead... If you can let me know the name of the Forum I would love to check it out and perhaps learn somemore things about this iPad...If you could let me know the name of the forum that would be great...

Your tip: https://discussions.apple.com/docs/DOC-3511

Bro I need ur email add to discuss some electronics assignment, I have show all ur post and relize that maybe u can help me.

<Edited By Host>

A few months back, I left my iPhone 4s charger at a hotel room in another state. I have not got around to buying a replacement so I have been using the iPad 10W charger for my phone. I have been doing this for a few months on a daily basis and have experienced no loss of battery life. No problem at all. .

However I have attempted to charge my iPad with my wife's iPhone charger- it will get it done but it takes FOREVER to finish the charge. For instance, the one time I tried to do this I plugged the iPad in at around 20% battery before I went to bed. I woke up to find the battery had only charged to about 70% overnight (7 hours) I am not sure that this would cause any damage to the batteries. I think you are safe- but who am I?

You can charge the iPhone with either the iPhone charger or iPad charger. It will charge faster with the iPad charger.

You can charge the iPad with either the iPhone charge or iPad charger. It will charge faster with the iPad charger.

Nothing will be damaged in any case.

Sorry for the incredibly late response but yes, everyone is correct, it IS fine to use both. Turned out that I was experiencing a battery flaw at the same time I started trying the switched chargers. Apple promptly replaced the iphone and since then I have used both without issue.

My bad -.-

Their was another post about this charging issue and I explained it all basic on my educational level with electronics. Their were some people who turned it into and utter and complete joke. 99% had no electronic background but made tons of dumb comments. As the post went on a couple people that were using the iPad charger on their iPhone ruined their iphone battery. Once these people started posting that these people stopped with their stupid replies. the reason volts, watts, and amps are put on chargers are for a reason or else why would they put them on.

I can get really technical with formulas on this but I will go with a very simple one. All Apple chargers are 5 volts. Amps is the amount of current flowing into your device to charge your battery. Watts are easily calculated V x A = W

Example. Charger is 5 volts and is 1 Amp so it has 5 watts (iPhone charger)

Charger is 5 volts and is 2.1 Amp so it is 10 watts (iPad charger)

That one I just rounded up the number like apple did.

Most PC's 5 volts and it is .5 amps so it is 2.5 watts

Slow. Charging your battery is best to get the most out of it but who would want to plug their new iPad into their PC and wait 24 hours for it to charge??? No one, not even me. Despite it saying "not charging" on the screen plug it in your PC overnight and remember what you started off with, turn off the screen, let it go for 4 hours, and YES it will charge at a VERY slow rate. The screen says not charging, but give it a try and you will see that it did charge up but very little.

Has anyone looked up the battery capacity of the new iPad verses the older generations??

iPad 3 11,500 mAh battery 42.5 watts

Pad 2 6,944 mAh battery 25 watts

So with their 5 volt charger 2.1 Amp 10 Watts you are fine because you are not going over the battery specs .Pretty amazing how they achieved that many mAh just by making it slightly thicker. Very technical how it was done but not for this discussion but it is almost double capacity.

Now let's talk iPhone.

IPhone 4S 1,420 mAh battery (1.42 Amps)

5 Volts x 1.42 Amps = 7.1 watts

iPad charger is 5 Volts 2.1 Amps 10 watts. Now you see the problem? Will it work Yes, but you are over charging (forcing to much current) your battery. End result you are decreasing the life of your battery.

Apple says you can use any charger and you can see above a simple formula in simple math. So why would you use a charger that is 2.1 Amps 10 Watts on a battery that is 1.42 Amps = 7.1 watts

Does anyone know what the cost is for Apple to put a new battery in your phone? I am curious on that one and would guess its not cheap.

Their is a formula in simple math. Can you use the ipad charger on your iPhone ? Yes. Will it shorten your battery life using the iPad charger on your iPhone? Yes.

This is the simplest formula broken down into simple math.