iPhone SE unexpected shutdown, unable to deliver peak power

Discussion in 'iPhone' started by ghanwani, Feb 18, 2019.

  1. ghanwani macrumors 65816

    Joined:
    Dec 8, 2008
    #1
    This evening, I took a couple of pictures and was texting them to 2 friends when I had an unexpected shutdown. The battery was at 17% when that happened. On boot up, I got the attached message and the battery read 9%.

    My understanding was that these shutdowns happen if the battery is not healthy. However, in my case the battery capacity is at 95% of original.

    Why was the battery unable to deliver peak power?

    Thanks.
     

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  2. Regular_User macrumors newbie

    Joined:
    Jan 27, 2019
    #2
    I had the same issue with SE, it started after ca 1 year of usage with the 93% battery health condition. I do not believe this health percentage is crucial here, the battery specs are just changing in time after number of charging cycles - it is well described by Apple in the phone section Battery->Battery Health->more information. In my case their explanation made perfect sense - the iOS shutdown my SE when it was used on lower battery charge like ca 20% and when I used it outdoors in winter cold weather for longer time so the battery couldnt handle it anymore on energy peak and system got it shutdown.
     
  3. JPack macrumors 68040

    JPack

    Joined:
    Mar 27, 2017
    #3
    Battery capacity is different from battery health. iOS only displays the capacity.

    Factors affecting overall battery health includes battery impedance. A battery's impedance increases with chemical age and also increases in cold temperatures.

    Your battery may be able to hold 95% of original capacity, but if it can't deliver that energy quickly enough due to increased impedance, battery health is poor.
     
  4. ghanwani thread starter macrumors 65816

    Joined:
    Dec 8, 2008
    #4
    That's a bummer. My phone is only 6 months old. But it was probably sitting at the store for a long time before I bought it, because the battery was stone cold dead when I opened it (would not power up).
     
  5. niji Contributor

    niji

    Joined:
    Feb 9, 2003
    Location:
    tokyo
    #5
    same issue with my 6s.
    after the update before last to iOS.

    i am not saying that apple purposely changed something in the way that battery handles power peaks in order to get users of 6s and prior iOS devices to upgrade, but, i am saying that what ever apple did to be causing these shutdowns now, apple can anticipate users needing to upgrade faster than we were before.

    just coincidence to apple failing to have a great 1st quarter sales result?
     
  6. C DM macrumors Sandy Bridge

    Joined:
    Oct 17, 2011
    #6
    Second best quarter result ever is gosling to have a great sales result? I bet many companies would love to fail like that.
     
  7. JPack macrumors 68040

    JPack

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    Mar 27, 2017
    #7
    Weak batteries are even weaker in cold weather - is the likely explanation.
     
  8. ftaok macrumors 603

    ftaok

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    Jan 23, 2002
    Location:
    East Coast
    #8
    OP, it could have been a one time thing, or it could be a symptom of an unhealthy battery. Seeing as how your battery health is at 95%, it's probably a one time thing. Snapping pictures and texting them shouldn't result in a peak power draw.

    I would go ahead and turn off the power management feature and see if it happens again. If it does, especially if you're not doing much, then it's probably a dying battery.

    NOTE - I wouldn't put too much stock in what iOS reports as Battery Health. If you have a Mac handy, use Coconut Battery to check on the battery health.
     
  9. JPack macrumors 68040

    JPack

    Joined:
    Mar 27, 2017
    #9
    The thing is, battery health isn't at 95%. That's only a measurement of battery capacity.

    It would be like measuring the blood pressure of someone who collapsed and then declaring they're probably fine. There are other health factors that aren't measured by iOS nor Coconut, namely impedance.
     
  10. ftaok macrumors 603

    ftaok

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    Jan 23, 2002
    Location:
    East Coast
    #10
    That's not how I interpret the OP's statement. I read the 95% as the current max capacity vs. the original max capacity. Apple lists this percentage in the Battery Health section of Settings.

    I think most people in the forum call this "Battery Health". Call it whatever you want to call it. For this discussion, the OP's Maximum Capacity is 95%, which usually would indicate a healthy battery, at least healthy enough to deliver the require juice during peak demands.

    Also, like I mentioned in my post, I don't really trust Apple's measurement for Maximum Capacity. Whatever they're doing, it's flawed, at least in my experience. Or maybe Coconut Battery is flawed ...

    In any event, a battery at 95% max capacity shouldn't have unexpected shutdowns when the user is just snapping pictures and texting them. There could have been something else drawing a peak demand (like a rouge app that didn't close properly) or the battery is truly in a weakened state.
     
  11. JPack macrumors 68040

    JPack

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    Mar 27, 2017
    #11
    Most people here seem to confuse battery capacity with overall battery health. It is incorrect to believe that a battery with 95% capacity means the phone shouldn't shut down. How much capacity a battery can hold has nothing to do with how quickly that charge can be released.

    Apple says "This performance management works by looking at a combination of the device temperature, battery state of charge, and battery impedance." Apple didn't leave out battery capacity in that sentence by mistake. Battery capacity and battery impedance are entirely different things - but both play a role in battery health.

    The Battery Health section is broken down into 2 sections:

    1. Maximum Capacity
    2. Peak Performance Capability

    Apple provides a percentage for Maximum Capacity. But for Peak Performance Capability, Apple looks at a combination of temperature, battery state of charge, battery impedance, and gives a pass/fail.

    Looking at battery capacity alone is like looking at blood pressure alone to determine health.
     
  12. iOZZY macrumors member

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    Mar 17, 2013
    Location:
    Stamford, England
    #12
    As soon as this happened to my SE the phone would switch off at 10% left no matter what. Mine was only 10 months old. Apple replaced it under warranty without quibble.
     
  13. ftaok macrumors 603

    ftaok

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    Jan 23, 2002
    Location:
    East Coast
    #13
    Yes yes. All of that.

    Without getting technical, a battery at 95% of max capacity is generally not that old. As batteries get older, they tend to lose max capacity as well as losing the ability to deliver max power. It's right there in your link.

    The OP has a battery at 95% capacity. The phone itself is only 6 months old (from time of purchase). He was down to 17% battery charge. He wasn't doing anything that typically requires peak power. Yet his phone shut off. Yes, the charge was at 17%, so that could be a contributing factor. But the other stuff would generally point to a different culprit, especially since this was the first time he had a shutdown.

    So my advice would be to turn the throttling off and go about his business. If it happens again, then he's probably got a bad battery. If not, then it could have just been a one-time glitch.

    What's your advice to the OP?
     
  14. JPack macrumors 68040

    JPack

    Joined:
    Mar 27, 2017
    #14
    Based on my experience, I would suggest a new battery, particularly if the device wasn't operating under extreme temperatures when the shut down occurred. I've replaced two devices with 93-95% capacity batteries in December under the $29 program. Shut downs occurred in the 10-15% range outdoors. Both of them already batteries replaced earlier in the year in Feb-Mar.

    For the OP, I think it comes down to whether they can live with a device that could shut down at 17%.
     
  15. niji Contributor

    niji

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    Feb 9, 2003
    Location:
    tokyo
    #15
    and so are glib explanations.
     
  16. chrfr macrumors 604

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    Jul 11, 2009
    #16
    If you bought the phone new 6 months ago, Apple should replace that battery under warranty without issue.
     
  17. ghanwani thread starter macrumors 65816

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    Dec 8, 2008
    #17
    It was given to me as a replacement because they broke my phone when trying to repair the broken mic and replace the battery.
     
  18. ghanwani thread starter macrumors 65816

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    Dec 8, 2008
    #18
    I checked with Apple. They said replacement phones only have a 90-day warranty. They ran diagnostics remotely and said the battery is bad but it will cost me $49 to replace it. Maybe I should just get an 8 and help them out.
     
  19. ftaok macrumors 603

    ftaok

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    Jan 23, 2002
    Location:
    East Coast
    #19
    If it were me, I would just get the $49 replacement. Maybe if you express some mild aggravation or lightly complain, they'll replace the battery for free. Yeah, I see that the replacement warranty is only 90 days, but you've only had it for 6 months. The battery shouldn't die that quickly.

    Incidentally, do you have the diagnosis from Apple, other than them saying "the battery is bad"? Is there a number or percentage? Back in the day (and maybe they still do), they would say that you could expect the battery to retain at least 80% max charge at around 300 charging cycles, or something like that.
     
  20. ghanwani thread starter macrumors 65816

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    Dec 8, 2008
    #20
    No additional info. They just said I need to take it in to confirm the diagnosis and possibly get it replaced (if it is confirmed). I think the battery is failing because the phone probably sat with no charge for a very long time before it sold (given to me).
     
  21. mrex macrumors 68040

    mrex

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    Jul 16, 2014
    Location:
    europe
    #21
    My 6S+ had the same issue and it shutted off around 40% even when it was new... now 3 years later i replaced the battery and no more shutdowns...
     
  22. abhim macrumors newbie

    abhim

    Joined:
    Feb 25, 2019
    #22
    I've been having the same issue with my SE which is roughly the same age as your phone. Also the fact that this thread is surprisingly new. Has this issue ever popped up before? In my situation, I was playing Pokemon GO and the first time it happened was two days ago. I had gotten a message on facebook messenger and I saw a wailord, the phone just froze, screen turned off with the backlight on and then the backlight turned off. I attempted to restart but it just turned back off. After charging the phone, it appeared to be fine. It happened again yesterday, while doing a Raid battle with other people. I got into the battle, and then it gave up. It seemed fine after plugging it into a battery bank. It was 70% and 80% respectively. It could be weather related (it was super cold outside), but the battery life was dropping steadily, but not really fast. It shouldn't have browned out, I doubt the SE SoC takes up that much power and it shouldn't have dropped 60% in the span of 30 seconds.
     

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