Can use ipad charger to charge iphone?

Well, having tried that for a month or so:

The iPad charger kills your iPhone battery.

If you hook up the iPhone to the iPad charger, the battery inside gets quite hot while charging, which is the cause of the battery's capacity decrease. Meanwhile the proper iPhone charger doesn't rise the temperate of the phone for me at all.

I'm trying whether charging the iPhone with it's original charger restores some capacity, but I guess the heat pretty much killed it irreversibly.

I've read through your subsequent posts but I'm going to post here because of your arrogance when you are clearly wrong. All lithium ion (or LiPoly) batteries use smart chargers which vary current and voltage dependant on the state of charge of the batteries. They can charge batteries with lower capacities because of their adaptive nature without problem and there is no reason why they should shorten battery life.

I am quite frankly uninterested in answering any of your puerile electrical engineering questions to rove a point so please don't bother trying to prove an incorrect point by asking any.

Me too.

Couple of months bsck I bought the latest iPad - I use the iPad charger with my iPhone 4S as it's by my bed.

My iPhone charges in 30 mins to full?

I get out of the shower in the morning and the 100% charge is 80% - within the hour it's down to 60%.

It's flat on no time. Back in the charger for 15 mins - back up to 100%.

My battery is stuffed.

On the other side of the bed, my wife has the same phone, bought the same day - her phone lasts all day.

I agree with Mr. Finch. The iphone may charge up faster, but the iphone will not use more current than a max amount. The iphone is nothing but a fancy resistor.

Ohm's law Amperes = Voltage/Resistance. The amount of resistence (unknown) and voltage (5v) is not going to change. Do the math. The current will only go so high.

The only way it would be a problem would be if the resistence is so low (close to 0) that the circuit becomes a short. Then it wouldn't matter if you are using the iphone charger or the ipad charger, both would overheat and destroy themselves. So if the iphone charger does not overheat (can supply enough current), then the ipad charger will have no problem supplying enough current. Even if you have a 5000000 Watt charger, at a fixed 5 volts , the current will never go above a certain level.

The problem that you can run into is the reverse which is to use the iphone charger to charge the ipad. The iphone charger can't supply enough current and can overheat and melt itself.

I agree with Mr. Finch. The iphone may charge up faster, but the iphone will not use more current than a max amount. The iphone is nothing but a fancy resistor.

I agree also - but my previous post it also a fact.

I think this is my third post ever? I'm a very busy person, so making a post for the fun of it, isn't going to happen.

Months have passed since I've been using the iPad charger with my iPhone 4S - My battery is at 50% after 3 hours, with no calls made - just checking emails and a few texts.

My wife's is at 80% at the same time/usage.

Regardless of the amps/volts/current debate - there is hard evidence that...

"Fast Charging" of the iPhone 4S with the new iPad charger is NOT good for the battery.

Mate, as per the previous post - I'm time-poor, so I'm not going to be "baited" by your comments.

I stated the facts from my usage of the phones/chargers etc.

Simple. Nothing more.

Whether you, or Apple agree - is as irrelevant as your post.

Whether you, or Apple agree - is as irrelevant as your post.

The only thing irrelevant is your post, stating unsubstantiated, erroneous and uninformed claims. The maximum charging rate and maximum battery is determined entirely by the charging circuitry in the phone itself - the charger has no control other than supplying the current required.

If your battery life is poor, the problem is in the phone. Unless you have a defective iPad charger supplying grossly excessive voltage, what you say defies all known laws of physics. Your ignorant and irrational belief systems have no value to anyone.

I was just posting what happened to my bloody phone man?

Chill out dude! It happened - or I wouldn't have posted it... jeeze...

"Dude", you have no clue how to interperate what "happened" - yet you do, only to make youself out as ignoranat or cognatively challanged. As to what you would find if you cut me open, I'm certain you couldn't cut your own way out of a paper bag.

You need to relax and get outdoors a bit..

Is that the best troll cliche put down you can come up with?

Irrelevant meaning:

You post is irrelevant since it's based on erroneous conclusions, and poor observation. Knowing the definition didn't stops you from calling "irrlelevant" an obviously relevant and accurate statement by Laurence Finch.

gamontecarlo wrote:

Well, having tried that for a month or so:

The iPad charger kills your iPhone battery.

If you hook up the iPhone to the iPad charger, the battery inside gets quite hot while charging, which is the cause of the battery's capacity decrease. Meanwhile the proper iPhone charger doesn't rise the temperate of the phone for me at all.

I'm trying whether charging the iPhone with it's original charger restores some capacity, but I guess the heat pretty much killed it irreversibly.

This is correct, the iPad charger might kill the iPhone battery, not directly by current, but the heat it generates while charging. My girlfriend used the iPad charger after she lost her iPhone charger, and now it's almost useless, after just a few weeks..

Quiz: Does 5W generate more or less heat than 10W?

If the iPhone gets hotter with the iPad charger, well my friends, then it draws more current or by some other reason produces more wattage. End of story.

And as we know, heat seriously degrades Li-Ion battery life.

So even if Apple says the chargers are compatible with multiple products, I would not recommend it in the long run, it's not worth the risk.

I charged my iPhone 4 almost exclusively with my iPad charger. Never got overly hot, never killed the iPhone. But you are saying we should believe your girlfriend's experience (1 instance which may no have been related to the charger) over Apple's engineers recommendations?

deggie wrote:

I charged my iPhone 4 almost exclusively with my iPad charger. Never got overly hot, never killed the iPhone. But you are saying we should believe your girlfriend's experience (1 instance which may no have been related to the charger) over Apple's engineers recommendations?

As long as it not getting hot while charging, it's no problem. And I did say it might kill your iPhone battery.

My girlfriends phone was just an example, my iPhone 5 gets much hotter when charging from 10-20% to 80%(Fast charge stage) with the 10W charger. But with the 5W charger it's "hot", but nowhere near the temperatures when using the 10W.

My brother charged his iPhone 5 with the 10W for a while, claiming he got better battery life with it, but it got worryingly hotter after every cycle, so he switched to his 5W.

Where does Apple recommend using the iPad charger for iPhone? It's compatible, yes. But that does not mean optimal or recommended.

But by all means, use the 10W to charge the iPhone, it's your phone 🙂

I seriously doubt that Apple's lawyers would allow them to list the charger as compatible if it was possibly going to damage the device in question or it was not recommended. I'll continue to listen to Apple instead of you.

You are clueless. It's not even worth answering. And all of your "points" have already been addressed in this thread. Try reading it.

Think about your house for a minute. The electric service is probably 200 amps. The voltage coming in is 220 volts. So the total power coming into your house is 200 x 220 or 44,000 watts. So why don't all of your 60 watt lightbulbs explode instantly? This is what you are saying when you say a 10 watt power source cannot safely power a phone that requires 5 watts.

It's not even worth answering.

all evidence to the contrary...!

Knert88 - you're wasting your time mate - although I'm sure you are experiencing these issue (as I did) Unless Lawrence sees it himself - it's mumbo jumbo - black magic.

I had my last post removed by him complaining and others complaining.

I have several Apple products, I love them - Sadly, I don't have a degree in electrical engineering, which means I can't feel heat from the phone and I also can't SEE the battery meter either 😟

Lawrence Finch wrote:

You are clueless. It's not even worth answering. And all of your "points" have already been addressed in this thread. Try reading it.

Think about your house for a minute. The electric service is probably 200 amps. The voltage coming in is 220 volts. So the total power coming into your house is 200 x 220 or 44,000 watts. So why don't all of your 60 watt lightbulbs explode instantly? This is what you are saying when you say a 10 watt power source cannot safely power a phone that requires 5 watts.

Hehe, 200A on the main fuse (or 200A breaker in the US) in a house seems a bit high, <63A is normal depending on the electrical system classification. A bit unrealistic example from a senior-engineer... Btw, be careful saying I'm clueless, that is a bit nonchalant as you don't know my level of education.

I know how a standard lithium-ion polymer battery charger IC works, I've made several of them in lab-classes.

And a regular ALC IC(Advanced Linear Charger IC) regulates the current by this formula: Ireg=Vreg/R1, let's say R1=4.5Ohm

This makes the IC more sensitive to DC-Source voltage dip, and a lower voltage dip makes a higher charge current.

My guess is that the 5W DC-supply(charger), has a bigger voltage dip than the 10W.

Examples:

5W delivers 4.5VDC at charge - this makes the charge current 1A

10W delivers 5VDC at charge - this makes the charge current 1.11A

Not much difference, but it might be enough to make a lot of extra heat.

And not to mention the IC power/heat dissipation, which of course increases in "overload" situations.

This is just my thoughts around the charger issue, and I might be wrong, but it doesen't make my(and many other) iPhone's colder when I use the iPad charger.

And of course, this does not happend to every iPhone out there, but the problem definitly exists, even with brand new phones.

So please Mr. Finch, could you explain the reason why many iPhones get hot when using the iPad charger?