1 4 5 6 7 8 Previous Next 342 Replies Latest reply: Sep 10, 2013 3:00 PM by ronhenderson2 Go to original post Branched to a new discussion.
  • 75. Re: Can use ipad charger to charge iphone?
    KiwiAdventure Level 1 Level 1 (5 points)

    Think about it. When you use your phone in the car using the car USB connection it also charges the phone. The phone regulates the charge.

  • 76. Re: Can use ipad charger to charge iphone?
    soldit2u Level 1 Level 1 (0 points)

    Thought about it.

     

    Phone still gets hot with iPad charger and battery drains quicker.

     

    Any more solutions?

  • 77. Re: Can use ipad charger to charge iphone?
    Zerotogo Level 1 Level 1 (0 points)

    Yes I have a solution. To all you guys who say that you can't use the iPad charger to charge your iPhone...don't use it!! Use, oh I don't know, your iPhone charger maybe? If you are right and everybody else is wrong, then let them find out the hard way. How about that for a solution? Cheers mate!!

  • 78. Re: Can use ipad charger to charge iphone?
    soldit2u Level 1 Level 1 (0 points)

    Smart arse.

     

    ...but you only qualify for the second word unfortunately ;)

  • 79. Re: Can use ipad charger to charge iphone?
    Smash209 Level 1 Level 1 (0 points)

    I find this interesting:

     

    http://www.idownloadblog.com/2012/05/21/apple-power-adapter-teardown/

     

    Still just a slightly better built power supply, but they try to make it sound smart.  With all this tech inside being so important, why didn't apple build a car charger?

     

    I agree with most everyone, the ipad supply should by rights not cause any problem, but it does seem to for some people I know.  Must be the 0.1 extra volt in the ipad 5.1V supply that's burning up everyone's phones!

  • 80. Re: Can use ipad charger to charge iphone?
    Jose10013 Level 1 Level 1 (0 points)

    merlin1128,

     

    I am not attacking your point that ipad chargers may do harm.

     

    Sep 5, 2012 9:38 PM:

    iPad 3       11,500 mAh battery 42.5 watts

    Pad 2          6,944 mAh battery 25 watts

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

                         5 Volts x 1.42 Amps = 7.1 watts

    ...

    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

    Your charger specs/calulations are correct.  Your battery specs are not.  mAh stands for miliamp hours.  11,500mAh in the ipad3 = 42.5 watt hours, not just watts (also at internal 3.7V btw).  In the iPhone4S 1,420mah ≠ 1.42 Amps... 1,420mah = 1.42 Amp hours.  3.7V x 1.42Ah = 5.254Wh

     

    Also you posted this Sep 5, 2012 9:38 PM:

    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.

     

    Yet at Sep 6, 2012 8:29 PM, 22 hours and 9 mins later:

    I used an old iPhone and obtained 2 other ones and put brand new batteries in them. Altered the charger to put out more than 2.1 amps and did 50 charge/discharge cycles on one. Did the same with te other one at 1 amp, and the other at .5 amps After that let all 3 devices sit for 3 days all at the same settings and the one that was charged at .5 Amps had the best battery capacity and the one with the altered charger was the worst?

    So in less than 24hrs you were able to go from not knowing the price of a new iphone battery, to replacing 3 of them yourself, charging them with different chargers, and letting them sit for 3 days to obtain your "results"?  Ok sure.

  • 81. Re: Can use ipad charger to charge iphone?
    trip1ex Level 1 Level 1 (0 points)

    I think everyone is wrong to some degree.  I don't think the ipad charger overcharges the iPHone.  But there is a good chance it  charges it faster.  And the faster you charge a battery the worse it is for long term battery life. 

     

     

    Some say the charging is regulated by the device.  But I don't think this is an entirely accurate either as some have painted it.

     

    After all Apple makes a more powerful charger for the iPad 3.  And this more powerful charger (or power supply) charges the Ipad 3 faster than the included charger.  Why is this if the charging is strictly regulated by the device?

     

    It seems that the charging isn't strictly regulated to a certain amperage.  But must have some acceptable range at the very least. 

     

    This is all easy to test.   Charge your iphone with both chargers a few times and make a note of charging times to full from x percentage.  See if a pattern develops. 

  • 82. Re: Can use ipad charger to charge iphone?
    Lawrence Finch Level 7 Level 7 (25,935 points)

    trip1ex wrote:

     

    I think everyone is wrong to some degree.  I don't think the ipad charger overcharges the iPHone.  But there is a good chance it  charges it faster.  And the faster you charge a battery the worse it is for long term battery life.

    A common misconception. Electric cars (which use the same battery technology as the iPhone) can charge at 120 V, 220 V, or 440 V. A typical electric car charged at 440 V with a high current supply can be completely charged in 20 minutes. Yet it doesn't hurt the battery, which has a 10 year warranty.

     

     

     

    Some say the charging is regulated by the device.  But I don't think this is an entirely accurate either as some have painted it.

     

    After all Apple makes a more powerful charger for the iPad 3.  And this more powerful charger (or power supply) charges the Ipad 3 faster than the included charger.  Why is this if the charging is strictly regulated by the device?

    Charging is regulated entirely by the device. The iPad 3 power supply can charge faster because it can provide more current than the included charger. The internal charger cannot charge the battery at a higher current than the 5 volt supply can provide.

     

     

    This is all easy to test.   Charge your iphone with both chargers a few times and make a note of charging times to full from x percentage.  See if a pattern develops. 

    Yes, I've done this. I am currently charging my phone with an Apple 10 W charger (5 v, 2.1 amps). It takes the same time to reach full charge (when the starting % is the same, of course) as it does with a 5 W charger that I previously used. I've also measured the temperature of the phone while charging. That is, I MEASURED it using a laser temperature probe, rather than saying "it felt warmer". It stabilized at the same temperature (~85 deg F) regardless of charger.

     

    I can imagine a scenario where the phone will get warmer and appear to charge faster with a higher current charger, but that isn't because the battery is actually charging faster. There are always background processes running in the phone. They are powered by the battery when the phone isn't charging, and by both battery/charger combination when the phone is connected to the charger. If a background process is busy sending or receiving data the additional capacity of a 10 watt charger can power the app while charging the battery at full current. However, a 5 watt charger will be putting current into the battery while the app is taking it out. There's less total power consumption, so the phone won't be as warm. And, as the battery is being drained while charging, it will take longer to charge. There are even scenarios that have been reported in the forum where the battery actually goes down while connected to power (usually to a USB port on a computer, which typically can only supply 2.5 watts).

  • 83. Re: Can use ipad charger to charge iphone?
    trip1ex Level 1 Level 1 (0 points)

    Afaik not a common misconception that the faster a battery charges the less its lifespan will be. 

    The difference wouldn't be night and day but measureable and a company could chalk up the difference as acceptable like, for example,  1000 cycles vs  900 cycles.  And note there are different battery technologies out there. 

     

     

     

     

    And by strictly regulated I mean some of these devices seem to have leeway to accept more charging current (than dictated by the included charger) if it is being provided.  Are all iPhones, for example, only able to make use of 1A of charging current?   Possible the newest iPhone models  can charge faster with a more powerful charger?  i say this because Apple made a larger 12W charger for their newest iPads in order to charge them faster even though the first iPad 3's at least came with a 10 W charger.

  • 84. Re: Can use ipad charger to charge iphone?
    yushenng Level 1 Level 1 (0 points)

    I'm convinced by Lawrence Finch's and Lumen's latest posts.  I'm a EE major who does a lot of electronics DIY work (micro controllers, embedded systems, robots, as well as household repairs), and I trust the measured results from Lawrence and Lumen (in actual current delivered with less than 1% variation between the two chargers, and temperature gained) to believe that: Apple has designed things such that it *should* be totally safe to use an iPad charger to charge an iPhone.

     

    I do see the reasoning in Merlin's points, but I believe that the data has proven that (as Lumen has said) that the charger/current regulator/current limiter is actually built into the iPhone device, and not into the wall adapter.  I cannot explain why Merlin's experiments showed greater battery deterioration when using the iPad charger.  It must have been chance: perhaps some batteries were worse than others in his test, and his test results happened to reinforce his hypothesis.

     

    I do acknowledge that some people have observed real-world deterioration in their iPhone batteries.  However, I am convinced that these issues were due to faulty batteries and/or faulty chargers built into the phone itself.  There's no other rational explanation.

     

    Again, I'm convinced.

     

    Another possible explanation of the disparity: maybe it's the charger/current regulator at fault in Merlin's and the other gentleman's experiences and not the batteries.  That is, perhaps both Lumen and Lawrence Finch received devices with working chargers/current regulators.  Maybe others didn't have faulty batteries, but had faulty chargers/current regulators built into their iPhones.  A faulty charger/current regulator could conceivably have this symptom of working fine with iPhone 1A wall adapters, but unable to cope with 2.1A wall adapters.  If this is the case, the result would be: battery life would be fine with the 1A adapter, but poor with the 2.1 A adapter.

     

    In any case, it's clear that Apple *designed* their iPhone so that it would behave completely identical with either adapter (or with any other vendor's adapter, for that matter).  However, if Merlin and others are indeed seeing battery life degradation when the 2.1A charger is used, it's either:

       - a one off coincidence...really attributable to the batteries that Merlin and others used in their tests

       - Or, if this behavior is fairly consistent, then perhaps Apple's built-into-the-device charging/current regulating circuit is frequently failing

     

    I'll take my chances and trust Apple's hardware design.  I'm going to buy a 2.1A wall adapter (i.e. an iPad charger) to use with my iPhone.... not because I Want to charge my iPhone faster (because it won't), but because I want to be able to occasionally use the same Lightening plug to charge either device at their fastest possible charging rate.

  • 85. Re: Can use ipad charger to charge iphone?
    Adrift02 Level 1 Level 1 (0 points)

    Wow, what a thread to stumble into.

     

    Couple things:

     

    Lawrence (and Apple depending on how you interpret "compatible") are the only ones that i see have provided data (measurements) to support that the iPad charger is works the same.

     

    Showing charging or battery life difference does NOT prove causality. There's many ways that you can use the phone to kill the battery faster or shorten its usable life. It doesn't mean the charger made the difference.

     

    As far as I know, USB chargers are pretty much all interchangeable (or at least that's how I've used them coming from many android phones). It makes sense that the phones determine the "pull" because they often need to cut down the charging rate to avoid "overcharging" the battery. That was one way I knew of to truly damage my old Epic 4g. You could keep re-plugging it in at 100% to overcharge it for more battery life (killing it in the long run). The fact that the regulation was done in the phone makes sense.

     

    Anyways, jumping into this thread for the first time, I've only seen real data for Lawrence's argument.

  • 86. Re: Can use ipad charger to charge iphone?
    Hornsan1 Level 1 Level 1 (0 points)

    Could you guys stop fighting and please help me. My question is right under this one in the hardware forum... Thanks

  • 87. Re: Can use ipad charger to charge iphone?
    Lawrence Finch Level 7 Level 7 (25,935 points)

    It isn't right under this one anymore, so a link would be helpful

  • 88. Re: Can use ipad charger to charge iphone?
    Morose1985 Level 1 Level 1 (0 points)

    I have to admit having just read through this thread, that I too am buying Lawrence's and Lumen's explanations.  They fit with my understanding from my engineering degree, although I have to admit as soon as I was able to drop Electrical, I did - but that was after 2 years of degree level study!

     

    I might be hijacking the thread a bit (apologies if so), but I have a very related question and want to exploit the expertise on show in this thread.

     

    I travel a lot and just bought an iPhone 5 in Europe with a European plug for the power charger.  I have an old charger with UK plug from my previous Android phone.

     

    Both Apple and Android chargers show the same output performance stats: 5v, 1A (i.e. 5W max output).  In a perfect world, they should then be identical.  However...

     

    Is there any reason to believe the Android charger could damage my iPhone?  Quality of components perhaps?

     

    I'm hoping to avoid giving Apple yet more money for a UK charger...

     

    Thanks,

    Martin

  • 89. Re: Can use ipad charger to charge iphone?
    deggie Level 8 Level 8 (46,495 points)

    No problem whatsoever, I had to charge mine with an Android charger the other day.

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