Sometimes iPhone powers off with more than 8% battery remaining!?

Discussion in 'iPhone Tips, Help and Troubleshooting' started by luisadastwin, Nov 19, 2010.

  1. luisadastwin macrumors regular

    luisadastwin

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    #1
    Really strange...

    Sometimes my iPhone can handle 2% battery for a long time without powering off...

    Other times, it's in about 8% and suddenly it powers off!! Once it was with 10%!!!!

    Is the battery dying? I have my 3GS only for an year...
     
  2. luisadastwin thread starter macrumors regular

    luisadastwin

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    #2
    There's something I forgot to say. I saw some forums about this and I really wasn't a good fellow to my iPhone's battery.

    I used for about a year the mophie juice pack air... and I used to let it charge with the iPhone for 8 hours or more (during all night)... also I would plug the charger when it was about 50% or more...

    I'm almost sure it was this kind of behaviour that messed up the battery because now I've been letting the battery go down till it totally drains out and charge it until it reaches 100% and IMMEDIATELY disconnect the power plug!

    It's been working fine now (only goes off at 2%) and it seems it lasts much more time now! Amazing!



     
  3. JamesMB macrumors 68000

    JamesMB

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    #3
    You don't have to unplug your phone when the charge reaches 100%...iPhone cannot overcharge.
    Apple recommends letting the charge drop below 20%, and then recharging to full, at least once a month.
    This is from the Apple website:

    Use iPhone Regularly

    For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Be sure to go through at least one charge cycle per month (charging the battery to 100% and then completely running it down).
     
  4. luisadastwin thread starter macrumors regular

    luisadastwin

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    #4


    Yes, I know that it cannot overcharge... But I talked with some friends and they told me that it is important to unplug when at 100% and not letting it connected all night. He has an app that sends an alarm when it charges at 100% so he can unplug immediately...

    thankx
     
  5. JamesMB macrumors 68000

    JamesMB

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    #5
    That is incorrect information...Actually, when the phone reaches 100%, it goes into a trickle charge, until it reaches "Full" charge. If you don't believe that, look at the green battery symbol, when the phone reaches 100%, leave it plugged in for a while longer and you will see that the green has moved up another "notch".
     
  6. luisadastwin thread starter macrumors regular

    luisadastwin

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    #6
    Yes, Ok. It is important to let it charge until 100% and a little more until the battery icon changes. Yes, I also know that. But that's when the alarm is activated I think :)

    So you say it is completely the same thing disconnecting right after full charge and let it plugged all night long?
     
  7. walterwhite macrumors 6502

    walterwhite

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    #7
    The phone hardware and software doesnt care if you leave it charging all night... I am on my 4th version (iPhone 4) and have always charged my phone on my clock radio all night long (8 hours or so) and never had a battery issue. The software turns off the charging when it reaches 100%. No reason to wake up to unplug your phone... if that was needed, the outcry from angry (and tired) consumers would be overwhelming. This was also true of all of the ipods from the very beginning.
     
  8. walterwhite macrumors 6502

    walterwhite

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    #8
    forgot about the main thread posting...

    The reason your iPHone may turn off at say 8% or even other times is that it isnt calibrated. The % you see is the softwares best guess at how much energy is actually contained in the battery. Since it isnt like a glass of water.. it has to use testing of voltage (power and current) to get a best guess of how much is left. Calibrate the phone like the previous poster... kill the phone dead once a month or so and then fully charge it. It should then have a very precise idea and allow you to use the phone closer to the "edge of dead" or 0%
     
  9. JamesMB macrumors 68000

    JamesMB

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    #9
    Yes, and if you leave your phone on, to run a clock app or something, the circuitry in the phone will allow the charge to drop to 98% and then charging will resume until it is full. Sooo if it sometimes has less than 100% when you unplug in the morning , that is the reason.
     
  10. luisadastwin thread starter macrumors regular

    luisadastwin

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    #10
    Thanks Walterwhite.

    I would like also to ask you all one thing:



    It is ok that I can plug on 50% or more or even leave all night the phone plugged... It won't damage or make the battery faulty. Ok. But if I unplug at 100% and let it drain to 0% every day, will the battery get a improvement in usage length? Or even battery life? Or is it really all a myth?
     
  11. JamesMB macrumors 68000

    JamesMB

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    #11
    Once or twice a month is all that is necessary! Other than that, you can charge it whenever or however you want. By the way, all this information is in your user guide, bookmarked in Safari, for your convenience.
     
  12. luisadastwin thread starter macrumors regular

    luisadastwin

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    #12
    I appreciate all your patience. And I already know that the user guide suggests the users to occasionally drain to 0% and charge till 100%.

    Ok. That is all we know. That's what You know, I know and everybody knows: we SHOULD occasionally drain to 0% and charge to 100%. However, I don't know if You answered my question directly or if You are still avoiding the direct answer.

    So I repeat. And you only answer if you have the patience. Don't answer if you don't want to or if you don't know the answer.

    Question: Does the iPhone battery (like any other battery in any electronic equipment) get some kind of improvement on cycle length of battery life if we drain till dead and charge till full everyday?

    Please don't answer what is "sufficient" or "necessary". I'm talking about optimising even if it is ONE MINUTE plus to the cycle length.

    Thank you very much.
     
  13. JamesMB, Jan 25, 2011
    Last edited: Jan 25, 2011

    JamesMB macrumors 68000

    JamesMB

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    #13
    Gosh..I thought that I had already answered this question.....NO!
     
  14. luisadastwin thread starter macrumors regular

    luisadastwin

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    #14
    Thank you for FINALLY giving me a direct answer ;)

    BTW, my iPhone sometimes restarts all the time on about 10%... like it doesn't have enough voltage to work, but enough voltage to start... Now maybe it is somewhat different...
     
  15. JamesMB, Jan 26, 2011
    Last edited: Jan 26, 2011

    JamesMB macrumors 68000

    JamesMB

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    #15
    Perhaps, if you were do a search, you would find a "direct" answer.
     
  16. luisadastwin thread starter macrumors regular

    luisadastwin

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    #16

    I will do that! But since you have a lot of wisdom on battery issues I thought you could say something about this also.

    BTW, this time maybe this question will envolve a more "descriptive" answer... ;)

    Peace.
     
  17. JamesMB macrumors 68000

    JamesMB

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    #17
    I gave you several descriptive answers, but you simply chose to ignore those. Some of the time a simple yes or no answer, is not only rude and demeaning, but simply leads to many more questions, which I patiently tried to answer.
    I'm sure if you use Google, you will undoubtedly find an answer you agree with.
     
  18. Carlanga macrumors 604

    Carlanga

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    #18
    Wrong, it should almost always stay plugged in, 1-2X a month you should do a complete drain to recharge and calibrate only, if not then you are losing life cycles unnecessarily of your battery.
     
  19. Rajani Isa macrumors 65816

    Rajani Isa

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    #19
    Not only that, the lithium-ion batteries used in the iPhone actually suffer from repeated full drains and charges, from what I read. Go ahead and charge it without draining it.

    The only way leaving it plugged in would really affect it is if it gets warm/hot from being left plugged in all night.
     
  20. luisadastwin thread starter macrumors regular

    luisadastwin

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    #20
    Sorry about that. I really perceived that your answers were ambiguous like:"don't bother with that" , "it is sufficient that you do...", "...the user guide says you should sometimes do..". So, not directly answering if there would be a way of enhancing the battery life / cycle length.

    I really didn't want to be rude. That was not my intention. I did not ignore your answers, I simply did understand that they were not totally answering the question.

    Answering that the behaviour X once a month calibrates the battery and that that is enough, does not necessarily indicates that a daily behaviour X will not improve life battery / cycle length. Well, at least I think so...

    BTW, sorry about the logic in previous post. What I meant was "sometimes battery reaches 10% and then it restarts all the time until it totally drains out."

    Well, once again, I'm sorry if you took it like an offense.

    Peace.
     
  21. luisadastwin thread starter macrumors regular

    luisadastwin

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    #21
    Cool! That sounds interesting! I'll read something about the Nickel vs Lithium chemistry technology!

    Thanks
     
  22. JamesMB macrumors 68000

    JamesMB

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    #22
    Yeah, I read that too, but until I have definitive proof, I think that I will just stick with what Apple recommends, since I'm on my fourth iPhone, and have not had a battery issue with any of them.

    The charging circuitry will terminate the charge, as soon as the charge reaches full, so the phone is not going to get hot from leaving it plugged in, if the phone is working correctly. If the charging circuitry is not working correctly, and it is in fact overcharging, you will know it pretty quick. Heat, and bulging battery are a couple of symptoms, but those are very rare.
     
  23. luisadastwin thread starter macrumors regular

    luisadastwin

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    #23
    I'm just curious about this one...

    You say that the iPhone "cuts off" charging when it reaches Full Charge. Like you were disconnecting the power plug, right?

    So, if you leave the iPhone plugged in all night, how does it keep the level always on 100%? Does it detect that is going for 99% and "turns on" the charging again till a full charge? Or does it actually charges just the enough power to keep it hanging in 100% (which wouldn't be precisely a charging "cut-off").

    Cheers.
     
  24. JamesMB macrumors 68000

    JamesMB

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    #24
    That has already been answered in post # 9.
     
  25. luisadastwin thread starter macrumors regular

    luisadastwin

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    #25
    Jeezzz... Thank you for putting up with me... sorry for all the trouble! When I read that post a few days ago, I didn't understand its meaning... Now I get it!

    Peace.
     

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