Previous 1 11 12 13 14 15 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

    I agree with your analysis. If you are used to using the phone alot or have active background processes that would account for faster battery depletion also.


    It's worth noting that the phone has thermal protection that will shut it down if its internal temperature gets too high, so even if it feels hot it isn't hot enough to damage the phone.

  • Ad Hoc Level 1 Level 1

    I must admit this has all been very amusing. I came here wondering if charging my iPhone 5 with my iPad charger may have somehow been responsible for it losing battery life at a rapid pace recently.  The phone had another defect so it was replaced yesterday.  I was concerned whether continued use of my iPad charger was still a good idea. I know Apple says it's "compatible" but I was hoping for elaboration. A


    So with all your combined knowledge, I still have no definitive answer as to whether I should use my iPad charger for my iPhone. So I'm making an executive decision: I'm gonna use the charger that came in the box.  Easy breezy.


    My work here is done. Thank you all for playing and pardon the interruption.


    As you were.


    <Edited By Host>

  • iinami Level 4 Level 4

    Thanks for contributing.

  • Ad Hoc Level 1 Level 1

    Really? These guys are going at it like rabid dogs and you edit out my pithy comments? No sense of humor. Too bad.

  • Bandit7 Level 1 Level 1

    It was suggested to me that I read this entire thread, which I have finally accomplished, after 3-4 evenings spending at least 1-2 hours per evening on reading this. All in all, I am glad I read this and want to thank the individual who suggested I read this whole "darn" thing. :-)


    I have learned a lot and would like to thank pretty much all of the contributors.


    Especially the individuals who have the highest qualifications and who have made EE  and computer science their careers. I am very glad, though puzzled admittedly as to how much of their own time, expertise and the efforts that these people give donating so much to helping others and their perseverance in threads, especially one like this one!


    So I watched the Utube video. That was that I thought. Extremely clear, tested and measured using the scientific approach, etc. I then remembered that I have my own Kill a Watt device and can really quickly check the videos accuracy.. So assuming my Kill a watt is still functioning well, and it is not an old one,


    I got some strange readings using it and was wondering if anyone could help clarify them.

    As follows)

    1) with my 10 watt 5 volt Apple power source connected to KAW (Kill a Watt) and the apple supplied 30 pin cord plugged into my IPad 2 while it was on, the wattage reading was 10.1 watts, some fluctuation to 10.2 watts. This was good and helped to possibly confirm the KAW is working.

    2) I unplugged the 30 pin cord from IPad 2 and plugged it into my apple 4 iPhone. Readings I got where 5.8 watts when phone was turned on, 5.5 watts with phone off.

    3) plugged my IPhone 4S into the 10 watt source next. Rather new phone. It read 6.5 watts power draw on the KAW while turned on and 6.2 watts when I put it to sleep.

    So being confused a bit, I thought of switching power sources. I switched out the 10 watt to my 5 watt apple cube.

    1) IPad draw was 6 watts

    2) IPhone 4 was the same as it was with the 10 watt source which was 5.8 watts while turned on.

    3) my new IPhone 4S still read at the same wattage level of 6.5 watts power draw while on the 5watt cube. as it also read on the 10 watt source. Asleep it dropped to 6.3 watts.

    I don't understand yet how the readings all match up to themselves on 2 different wattage Apple Dc power sources which would be perfect except for how does the 4s pull 6.5 watts from both a ten watt and a five watt source.


    My apologies if this was too long a post. I also umm... Am one of "those" people who used my IPad charger on my first iPhone 4 and also noticed severe loss of capacity after doing it for a while.

    But I suspect that this may have to do with the very poor quality of my grid supplied utility electric power coming in through ancient wires, in a 100 year old building, in a rather rough neighborhood which gets browned out first whenever there are power shortages.

    Actually I wonder if some of these other posts about IPad power source adapters burning out their I phone batteries may be experiencing lower quality "grid" supply as well. I have read 3-4 different articles, 3 of them on Wiki, all stating that the power supply on a lot of the grids, especially here on the northeastern sector, has overall very low quality of power.

    Because of extreme old age, and an incredibly larger energy demand then when the systems were first built for a smaller population with a lot less air conditioners. same grid which also did fail completely that summer some years back.

    Also i read that around my area,  when the sinusoidal wave forms coming in on our grid , when they are measured, are not pure sine wave forms anymore, like those  that one sees on newer grids further out west.


    I guess this is several questions rolled into one long post. I would like some advice as to my readings and what about

    The idea that Quality of received mains electric power may be what's affecting some of the internal charging circuitry over time when exposed i phones are being powered using above mentioned quality of power received? Thank you everyone. Cheers!

  • Bandit7 Level 1 Level 1

    I did probe though that regardless of which power source I used, the phones did not draw more power from the 10 watt one then they did from the 5 watt one. And that is what this thread's focus sometimes meanders back to. :-)

  • modular747 Level 6 Level 6

    1. The wattage you measured is what the power sources are drawing from the AC outlet.  The ratings 5 or 10 watts are what ite can DELIVER to what's connected to them.  To measure that you would have to connect a meter BETWEEN the power source and the phone.  The delivered power is always less than what is drawn from the AC.


    2. The local voltage can have an effect on charging , but minimal since the phone has a regulated charging circuit


    3. The non-sinusoidal wave form may make the device buzz, but won't have any practical effect on charging.  To do so, it would have to be so grossly distorted that most electronics attached to the grid would destruct.

  • Bandit7 Level 1 Level 1

    Thank you. That all makes perfect sense.

  • drbennett75 Level 1 Level 1

    From one engineer to another: thank you.  Seeing someone offer this explanation while simultaneously interchanging Wh and W was making my head hurt.


    Simple lesson kids: in this situation, concerning I = E/R, E is the only variable, and all USB chargers are likely regulated to 5VDC output as long as the input falls somewhere between 10-15VDC. 


    Furthermore, most devices containing lithium battery chemistry have additional charging circuitry built into the device, so even if you tried to feed it with a higher rail voltage, the phone's internal charger control should regulated to the necessary float level for the battery.

  • Cmndrred Level 1 Level 1

    Quick tip: if you ever lose a charger, just go to a hotel front desk and tell them you lost one. They almost always have a big box of orphaned charges that you can dig through. Been doing this for 15 years...and have donated a few to the orphanage as well. Works 90% of the time, and if they say no, just go to the hotel next door....

  • AYRONSENNA Level 1 Level 1

    Lots of great info here I wanted to say thank you to those who keep their calm and post in a respectful manner.  My situation may be a little different but I thought I'd share anyways.


    At work I use my iphone 5 to tether to my laptop which I use all day to browse online, occasionally stream soccer or hockey or basketball games etc.  now this is sort of a rant I guess but I'm very frustrated with my iphone 5 at work. Its not the phones fault but I am in a very low metal clad building so the signal isn't the best. I am usually at 1-3 bars 3G unplugged. As soon as I plug in the phone it drops 1-2 bars hovering between edge and 3G. Now that's just me whining that my iPhone 3GS , 4 and 4s never had that signal drop plugged in but it is what it is I guess I just wanted to explain my situation leading up to today (which relates to the thread a bit).


    So my routine for the day goes..


    1. Get to work. Power off and plug in the phone for first 2 hrs.

    2. At break turn on my phone and unplug it so I get best signal possible.

    3. Watch battery sink like an anchor. During a 20 minute brea I can watch it go from 100 to about 70%.

    4. Plug back in.. Power off or airplane mode. Hope for as much charge as possible. Or if I'm still connected ill deal with the disconnects and lag and plug the iphone in while tethering. If being used while tethering my battery will hold or slightly drop in % plugged in.

    5.. Repeat every break etc until later in the day I'm at <5% where I have to stop tethering and power off and charge.




    SO end rant about my battery usage and drain issues lol but today I thought maybe I would go out and buy a iPad charger and I did. I've learned that perhaps it won't do anything but kill my battery but I believe there is sufficient evidence to support that nothing will happen. I had hoped that maybe the iPad 10w charger I bought would allow more faster charging to be able to keep my battery up while being used but ill find out Monday.


    After absorbing a lot of info on how the charging works .. I'd tethering is a big drain would it make sense to wish that with a 10w charger my phone will at least remain at its charge level while being used or actually charge during use due to the extra juice available ? I hope that even makes sense :o

  • Michael WS Level 1 Level 1

    I think it's matter of designed battery "charge rate" rate vs "charge capacity" and designed battery heat dissipation.


    I can only assume an iPhone charge circuit has two modes.  Allow full charge capacity i.e., trust the max charger amp output of 1 amp from 0 to 90% charge then switch to trickle mode from 90 to 100%.  I observed these two modes from a downloaded iPhone charging application.


    Given the above, charging at a max of 1 amp from an iPhone charger will not exceed the charge amp threshold of the battery for designed heat dissipation and other unknown factors that may influence battery life.


    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.

  • Michael WS Level 1 Level 1

    Keep in mind that yes, heat = work = watts.  But we are dealing with constant input volts.  Therefore, max amp flow is the variable here.  I would think that voltage drop across a given battery type and battery resistance plays a role here as we'll, but these specs are unknown to me.

  • DACCG Level 1 Level 1



    That sounds really good, I think that the 10W charger (if you bought it at an Apple Store, it might be a 12W because Apple 'updated' it to charge better the new iPads).


    Anyways, I am really looking forward to see how your iPhone 5 does while tethering and charging with the 10W charger. This is my guess: It will definitely charge the battery (I mean, it will increase your battery charge level) while tethering, however, the iPhone might get hotter than when you plugged it with the 5W charger.


    Will keep an eye on this thread by Monday evening!

  • Lawrence Finch Level 8 Level 8
    Mac OS X

    You could connect a 100 watt charger to the phone, and it would still only charge at the 1 amp (5 watt) rate. Because the "charger" is not a charger, it is a 5 volt power source. The charger is built into the phone. There's a video in this thread that demonstrates this. It shows the power supplied by the charger on a wattmeter. And it is the same 5 watts using the 5 watt charger or the 12 watt charger.

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