Previous 1 12 13 14 15 16 Next 342 Replies Latest reply: Sep 10, 2013 3:00 PM by ronhenderson2 Go to original post Branched to a new discussion.
  • AYRONSENNA Level 1 (0 points)

    Mr Finch I fear you are correct. I will try anyways just to see what happens since I already have it (bought it earlier in the day before I searched this thread).


    One thing I felt like mentioning is that we have the wall chargers around the house. For the iPad and our iPhones. We also have a iMac we bought in 2009 or 2010 its the 27" version. Perhaps we are completely wrong but we both believe the iMac charges our stuff much faster. I just asked my wife and she believes it like its a fact. I remember last year when I had the iphone 4 me and the wife would sometimes race to use the iMac cable so we can get our phone on it.


    Ill admit I didn't watch the video I ended up continuing to read the posts. Ill watch it now.  My last hope for a good signal at work without killing my phone battery is to get a signal amplifier and try to get an antenna mounted somewhere high.  If I can get a little better signal for 3G or even lte with it plugged in ill be happy as can be.

  • Wolf Harper Level 1 (40 points)

    You can never, ever trust your "sense" of the facts.  Humans have very strong biases that makes them see what they expect to see.  People who say it's warmer from the iPad charger may be doing other things different, like taking it off immedately after the charge wraps up rather than waiting longer and having the phone cool.  Hard science is hard. 


    >> One of my friends said, if a wire is a pipe, Voltage is water and the current is the pressure at which it gets the water through the pipe/wire.


    You got it wrong.  Voltage is the pressure.  Current is the flow.  You decide how much flow to draw.  Drawing more flow decreases pressure somewhat.


    Imagine an inflatable structure that inflates with water.   It is rated for 100 gpm at 5 psi.  Your faucet outputs 5 gpm at 40 psi.  Can you fill it, yes, but you better be paying attention near the end.  That is what charge controllers do.


    >> Forget about the charging circuit for a minute here. This is a theoretical question(I am not asking you to perform it). If I pull out the battery off the phone and provide it 12v, it will most likely kill the battery


    Well keep in mind lithium batteries typically have internal charge controllers.  The controller would probably either shut off to protect the battery, or PWM down to the correct voltage.  Assuming you bypass that... eventually yes, but you would have some small amount of time where the battery would charge very, um, robustly before it overheated.  In fact this is exactly how quick charging is done.  My 15 minute niMH charger has a fan on it to cool the batteries.  


    >>>  So now you see why they sell car chargers, motorcycle chargers, and ones with variable charging rates. Please explain that one why their is not one charger for all car and motorcycle batteries.


    Because copper costs money and for different modes.  Burst current to assist engine cranking; quick charge but it will eventually overcharge so you must mind it; and slow charge that you can leave on 24x7.  Welcome to life before charge controllers.  


    >>> What voltage does a car alternator put out?


    Varies by accessory load and charge load.  A just-cranked battery is very hungry and pulls the voltage down.  Yes it pulls the voltage down on the alternator output pin.  It's not all wiring losses.  Once everything balances out should be 13.8v but the better regulators also compensate for temperature (I forget the rate).  The best have a temperature probe inout so you can stick a temperature probe inside the actual battery box.  This is more of a big deal on locomotives.   


    >>>> Should twice the flow be allowed by the charge circuit in the iPhone, the charge gates  are wide open i.e., the charge circuit design assumes 1 amp max output but still accept a two amp flow, may induce extra heat in the battery thereby negatively impacting battery lifespan.  ...  The charge circuit may prevent overcharge, but may not regulate the charge rate.


    No, that is wrong.  The charge circuit DOES regulate the charge rate.  An intelligent charge controller which does that is mandatory for lithium ion batteries.   That is not the wall cube.  That is inside the phone and quite possibly inside the battery itself.


    If you put a low flow shower head on your shower... It will slow down flow.  If I then replace all the pipes in your house with pipes twice the size, your low flow shower head flows exactly the same as it did before. 


    >>> Since you have such expertise answer these questions too. What voltage reading will you get on a 220 volt 3 phase piece of equipment coming in from testing supply to supply? What reading will you get testing one supply to ground? Do you need a neutral wire to use this 220 bolt 3 phase piece of equipment ?


    Trick questions.  You already specified phase to phase as 220v. You did not specify wye (defined by having a neutral, in the middle of the Y) or delta (defined by no neutral).   On wye the ground is usually at the same potential as the neutral (220 divided by sqrt(3)...) but there is no standard for ground location, it can be any wire, phantom locations (wild leg, center of delta) or ungrounded.   Ungrounded is awesome if you're trying to make 600vdc. 


    >>> What size light bulbs do they use for an L train that ONLY has a 600 volt power source coming in?

    They used 120v bulbs wired in series in sets of five.  Bulbs are specially designed to snuff 600vdc arcs.


    After 1920,  L-cars got a 32v battery circuit charged by a 600v MG set or chopper.  Some or all bulbs run off these, these are obviously 32vdc.  Nowadays they are fluorescent and are moving to LED.


    You did ask :)

  • HyperNova Software Level 6 (8,655 points)

    It doesn't matter how much logic or rational thinking you use; there will always be someone who ignores reality and will search for the answer they want until they get it.

    Good narrative.

  • ksteiger Level 1 (0 points)

    When I use my iPad charger on my iPhone I am visited by paisley alien creatures from the planet Zeutron.
    Apple's lawyers are OK with this.

    Seriuosly, though, this whole argument is ridicluous. If this were the case I would not be able to use batteries in my caera that supply higher current levels... (measured in amperes) The large ones would blow up my cam. That in itself should be the end of this thread...

  • kokhean Level 1 (0 points)

    Why not just ask someone reliable? I emailed Mr. Schiller from Apple and I got a response.




    So what's the verdict? Yes, you can use your iPad charger to charge your iPhone and it will not cause any damage to the battery or iPhone

  • Bandit7 Level 1 (60 points)

    He did ask. But why did you actually go to the effort to answer him? :-)

    Excellent response by the way. A very good narrative indeed.

    As for voltage levels on L Trains, the last time I checked, I am pretty sure I saw Apple's webpage entitled Using IPads in that address bar somewhere near the top of this entire thread.

    Did anyone else notice this?


    If only people were actually hard wired to look at the facts instead of continuing to assert their false beliefs on the rest of us... Well said, Michael.


    Since the topic in this discussion seems so often ignored,  I am going to paraphrase William Paley, the 18th-century English Christian Apologist. This quote has been misattributed very often to Hubert Spencer.


    "There is a principle which is a bar against all information, which is proof against all arguments and which cannot fail to keep a man in everlasting ignorance — that principle is contempt prior to investigation."


    I actually first came to this discussion believing erroneously that the charger was in that pretty empty power cube,

    I actually did watch the YouTube Video, I saw soon  that I was wrong, I learned a whole bunch of new and exciting stuff when I was faced with the simple truth, I have a kill a watt meter just like that real nice guy in the YouTube video had, and guess what? Mine read pretty much the same wattages as his. Lesson Learned. Next Please?

  • Bass12 Level 1 (0 points)

    I dont think anyone is just going by their belief, they must be observing something different or else this thread wouldnt have attracted so much attention. No one is debating the fact that the Ipads charger can be used on the iphone. But every person that came in here has noticed that the Ipad charger is charging their phone at a much rapid paste and many have also noticed that their battery is draining much faster after they used the Ipad charger. When you have one person claiming this, it may not hold much weight, but there are many that came in ehre asking the same.


    I plugged in two iphones one to USB and one to ipads charger, and indeed using the ipads charger is charging at a much faster pace, maybe its my USB thats not putting out but its what I have infront of me.


    I also did notice after charging with the Ipads charger my battery was draining quicker, and once again confirmed by setting both battery brightness on both phones to be the same and the phone that was charged using the ipads charger was draining faster. I did a battery reset and the issue was gone and started draining at a normal pace again. These are all observations reported by many and not just one person. But yea we can use the Ipads charger as Apple claims, these are facts, the end result has caused one one of the longest threads on the floating around the internet. Why? Somehow people reporting what they observe as turned into a bullying match on here. Now the slower you charge a battery the less capacity it looses per charge cycle. This goes for any battery, consider these old things weve been taught when people are reporting they noticed their phone is depleting much faster after using the Ipads charger, rather then being so arrogant. Although Apple states you can use their Ipad charger on the iphone, after what I experienced and from ym personnel experience, I wouldn't do it unless in an emergency.

  • Control System Guy Level 1 (0 points)

    I love this thread; it’s where engineering meets new age science. I happen to be in the engineering camp. I am boring engineer with a “put you down” number of years’ experience. I have used lots of DC power supplies in many different configurations. I agree completely with Lawrence Finch at the beginning of this thread and his legion of followers and still do. The impedance of the receiving device determines the amount of current drawn.


    Now I going to tread on scared ground and say that some regulator circuits might not have been designed properly. There are “smart” (I personnel hate this term) chargers. My guess is that one of these devices when it found a rich source of current, it lowered its impedance to speed up the charging process. But said device wasn’t smart enough to recognize that it was going to overheat the battery at that rate.


    So my advice is if the phone is getting hot to the touch don’t use the higher wattage supply as an everyday charger. It’s okay for emergencies but the effect is cumulative. (Oh, I forgot to mention, I deal with battery backup systems too.) Heat is their enemy. We air condition all our major battery systems. Depending on the battery, you can cut the life by way more than half by raising the battery temperature by less than 5°F.)


    So the second take away my children (there I go again, being patronizing) DON’T leave phones, etc. in cars during the summer. Also, store your battery powered tools in the house not the garage. One more passing comment, batteries don’t like the cold either. They don’t lose power but they won’t give up the power as easily so stuff can stop working at cold temperatures.

  • BlueBay Level 1 (0 points)

    This discussion is awesome, I respect and believe everyone might be right on his/her own, I'm not technical but only pondering... being COMPATIBLE and what Philip Schiller says "... CAN be used..." instead of "iPad charger REPLACES the iPhone charger" then it would really be a legal battle involving Apple lawyers if the iPhone can be proven damaged by the iPhone charger guys... a battery overheating upon charging I believe is definitely not a good sign... There must be some other underlying factors inside the iPhone or iPad circuit not discovered in this discussion yet, 'cos we know at least by now that the "charger" is only an energy/electric provider. Someone (our technical engineers) should dissect these two products circuitry and let us know!

  • BlueBay Level 1 (0 points)

    I meant "... damaged by the iPad (lol) charger guys... "

  • HyperNova Software Level 6 (8,655 points)

    Let's let this thread die already.

  • Tyler pm103 Level 1 (0 points)

    lawrence finch is right sorry man you were outsmarted, your a hardass so you wont agree but he is right.

  • i Smack Level 1 (0 points)

    Gotta agree with Finchy here. Don't have an electrical background, just in I.T. but what Finchy says falls in line with what I read a couple years ago:


    Anyone with a Mac with both OSX and Windows will notice their iDevices charge much faster on OSX. This is because OSX is programmed to recognise the power requests from the iDevices and dishes out the correct amount accordingly.


    edit: to clarify, it sort of backs up the idea that the iphone/ipad is capable of adjusting power. It doesn't just simply lie back and receive it.

  • kelvinnguyen Level 1 (0 points)

    Very simple.


    1Ah = 3600 C (coulomb)

    1 mAh = 3.6 C


    Your iPhone needs total charge Q = 1440 mAh = 5184 coulombs


    Your iPhone has a fixed battery inside. So capacitance is constant. C is constant.


    C = charge/voltage = Q / V


    V is constant (iPhone/iPad charger supplies 5V)


    Q = charge_current x charge_time = I x t




    C = Q / V = (I x t) / V

    => charge_time  t = ( C x V ) / I

    in this equation we have C constant, V constant (5V).

    Therefore, higher charge_current will reduce charge_time.


    Your iPad charge gives 2.5 amps (compared to 1amp charger), it will charge your iPhone faster.

    There is no other side effect from this equation.

  • Bass12 Level 1 (0 points)

    Kelvin are you in NYC? Drink and dinner on the house partner. Thank you and hope this sets the record straight here. Which Iam sure it wont, but for sure aid.

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