Previous 1 5 6 7 8 9 Next 342 Replies Latest reply: Sep 10, 2013 3:00 PM by ronhenderson2 Go to original post Branched to a new discussion.
  • Lawrence Finch Level 8 Level 8
    Mac OS X

    Any quality USB charger that can supply a minimum of 0.5 amp should work with the iPhone. I have several aftermarket chargers that I use interchangeably. The industry did something right for once with USB; it's a world-wide standard, and all devices manufactured to meet the standard should be interchangeable.

  • tonefox Level 6 Level 6

    For what it's worth, I have from day one charged my iPhone 4 with the supplied charger, an iPad charger, a Bose SoundDock, and at least three anonymous USB plugs that cost at the most £1.50 from eBay, sometimes with an included car charger, through a variety of cables from Apple's down to cables at well less than £1.


    I have had zero problems with the phone since I bought it.

  • Adrift02 Level 1 Level 1

    FYI, did a test with my one week old iPhone 5 trying the stock base and iPad 3 base. They charge at the same rate as expected:



    7:58 end 96%

    6:08 start



    4:45 end 96%

    2:56 start


    That is one **** of a coincidence if it's charging at a different rate.

  • rgvspeed Level 1 Level 1

    You're link might be the answer and would make sense.


    Copy/paste...The USB output also has specific resistances connected to the data pins to indicate to the iPhone how much current the charger can supply, through a proprietary Apple protocol. An iPhone displays the message “Charging is not supported with this accessory” if the charger has the wrong resistances here.



    What's it said that was interesting is that the iPhone and the charger use the data pins.

    The phone can detect what type of charger it is and the changes the way it operates.


    .5 v USB charge (eg. Laptop)

    5watt charger

    10watt charger


    So depending on what the phone is plugged in to depends on how the iPhone charges it self.if the phone knows it can draw more current it does thus charging the phone quicker.


    Also if its plugged in to a laptop it knows it can only draw a lower current, to avoid damaging the laptop from drawing to high of a current it can supply. So it would be a slower charge rate.


    This would be an answer and explain why people are experiencing these problems.

  • Motagaly Level 1 Level 1

    I’m not even an engineer; I start with that, as this thread is full of hate 


    I will not go into the technical details and the dilemma of pulling electricity vs. pushing electricity (whether Power is drawn or pushed) and which component is responsible for the regulation, and which side of the equation do push the other “if you know what I mean”, as it was a nightmare for debaters at the college era.


    But if the iPad charger will charge the iPhone faster and would kill its battery (1440mAh) in a few weeks, although it was mentioned by Apple as compatible, then I wonder if it would charge “faster” the iPod Nano 7th generation (220 mAh), or, iPod Nano 6th generation (105 mAh), or, Shuffle's (51 mAh). And I mean faster like in 5 minutes and kill it in one day by the same analogy! Since all of the above is compatible with the 10W iPad charger and guess what, with the new 12W iPad charger as well.


    Please excuse my ignorance, I’m not an Engineer, I am a Physicist!!

  • Lawrence Finch Level 8 Level 8
    Mac OS X

    As I recently determined by actual measurement (which you as a physicist would appreciate), and reported in this thread, the iPad charger does not charge the iPhone faster than the iPhone charger does.

  • Tom Perkins1 Level 1 Level 1

    Ewwwwww! But I love it when you talk nerdy to me.

  • bb340 Level 1 Level 1

    Actually a question not strictly a reply. I think I have read everything so far. My question: The Battery Monitoring App I use indicates the same time count down while charging with either the iPad or the iPhone charger, or for that matter one of the USB outlets in an RCA device that plugs into a standard 110 home electrical outlet. Is that a  reliable measure of the charge rate? And, does the heat being generated come from the battery itself while being charged, or some kind of internal resistance?

  • Lawrence Finch Level 8 Level 8
    Mac OS X

    You need to read the specs of the power source. The iPhone charger can supply up to 1 amp. The iPad charger can supply 2.1 amps. But the iPhone will only use 1 amp, so the iPad charger will be running at less than its capacity (nothing wrong with that, BTW; the incoming power in your house can supply 200 amps most likely, but you will never consume that much). If the RCA device can also supply 1 amp or more then it will take the same time as the iPhone or iPad charger to charge the phone. Your battery monitoring app confirms this.


    Most older computer USB ports can only supply 1/2 amp (0.5 amp), so the phone will take twice as long to charge using a computer USB port. Some newer computers, and most Macs, can supply 1 amp to at least 1 device, so if your computer qualifies then it will charge the phone as fast as the wall charger. With a Mac the first device to "request" more than 0.5 amps will get up to 1 amp; additional devices will be limited to 0.5 amps.

  • rgvspeed Level 1 Level 1

    Lawrence, if you don't think the iPad charger chargers the iPhone faster than an iPhone charger.


    Then how do you explain the iPhone charging slower via USB connection?


    Going back to the URL about the the break down of the charger it shows that the charger indicates to the phone how much current the phone can draw to charge at optimum speeds.


    It uses different resistances though the data pins.


    Did you check out the charger break down.

  • Adrift02 Level 1 Level 1

    Didn't he just explain slower USB charges (0.5 amps)? Also, as was confirmed above using the timed charging device and my own personal test, the iPhone and iPad chargers charge an iPhone (5 in my case) at the same rate.

  • Lawrence Finch Level 8 Level 8
    Mac OS X

    Thank you Adrift, for answering. rgvspeed, if you go back in the thread I did timed measurements including temperature measurements using a 1 amp and a 2.1 amp power source (both Apple), and it took the same time to charge with both, and the temperature of the phone was about the same with both (measured, not "it felt hotter").


    In that message I also explained why some people might see a faster charge with the 2 amp charger, and it wasn't because the phone charged faster, but because there was a battery drain that slowed the charging with the lower capacity power source.

  • rgvspeed Level 1 Level 1

    Thanks , one more question.


    How does the iPhone know it can only draw .5 amps when pluged in to

    A USB connection not a wall charger?

  • Lawrence Finch Level 8 Level 8
    Mac OS X

    It doesn't have to "know". That's all the connection can supply.

  • Leonard Hou Level 1 Level 1

    When a device tries to draw more current than what the USB port can supply (which is .5 amps in your case), the supply voltage of the port drops below 5V.


    That could be a way how iPhone "knows" that it cannot draw more current.

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