iPhone 7(+) Have I just joined the "bad battery" crowd?

T Coma

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Original poster
Dec 3, 2015
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Flyover Country, USA
My iphone 7 was fine last year in cold weather. Thursday it died numerous times after being exposed for a few minutes at a time in "frigid" above-freezing weather. Is my battery shot now? Get a new one?


TL;DR - bought my iphone 7 in Sept of 2017. The battery life has been acceptable for my use, in that it generally will last an entire day. There has been some decrease in battery life, but not too dramatic I guess. The "battery life" app says a wear level of 13%, FWIW.

I've read enough stories of cold affecting battery performance, but I personally haven't experienced that, certainly throughout last winter, with plenty of outdoor use. Yesterday was a different matter though. I was involved in a minor accident with a taxi, which didn't even prompt a call to the police or exchange of insurance info. We both checked our vehicles and, seeing no damage, we shrugged our shoulders and went on our merry ways. Well, he did, anyway. My 20 year old truck wouldn't start. It seemed like an easy diagnosis (it was) but I could hardly do it at a dangerously (obviously) busy intersection in a city known for its traffic. I needed a tow the one mile home. As I'm trying to contact tow companies, the phone with 50%+ full battery would shut off after being on hold for a few minutes or even mid conversation. I'd go into a local store (t-mobile coincidentally - and no, they were no help) to warm the phone up and I could use it again. I'd go back out to stand by the truck and the phone would crap out again. Happened 3 times until it just wouldn't turn on anymore. Lucky for me, there are enough tow trucks going through this intersection that I was able to flag one down and get a tow back home.

As I suspected, the starter was shot and only needed this little bump to push it over the edge, so I was able to grab a new one and swap them out yesterday. I mention this only because while I was outside working on the truck, listening to podcasts, phone in my pocket, it died again. I brought it inside to plug it in and it went from 0 to 70% in maybe 5 minutes?

Again, I know that others have made similar claims before, but I'm quite sure I never had these issues in similar circumstances. Thanks for reading this far - Sorry for the verbosity.
 

BasicGreatGuy

Contributor
Sep 21, 2012
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In the middle of several books.
I would monitor your phone battery the next several days. Also, make sure to see what the battery health percentage says in iOS. It is not uncommon for the phone to shut off when cold. Most times, there is no permanent damage. If after 3 - 4 days, iOS says your battery is below Apple standard, or you continue to experience shut downs, take your phone to Apple. You may need a battery.
 

now i see it

macrumors 601
Jan 2, 2002
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Only a newish battery can withstand the rigors of freezing temperatures. Li-ion batteries can fail suddenly. The deterioration due to age is not linear. Maybe a 1 year old battery is too old to be able to function well in freezing temperatures. I doubt you'll get any sympathy from the Apple Store.
 

JPack

macrumors 601
Mar 27, 2017
4,762
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You have an 18 month old battery. Many users need to replace their batteries at the 24 month mark.

Battery impedance increases in low temperatures. No app can measure battery impedance. Only iOS can. But it isn't displayed to the user. iOS only tells you if the battery should be replaced under Battery Health.

Apps including Coconut can only tell you the battery capacity. That information won't tell you if your battery will fail in low temperatures.
 

StellarVixen

macrumors 68020
Mar 1, 2018
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Your battery is more than a year old, so, yes, it happens. My 6S shuts down in near or below 0 degrees Celsius (32 F) temperatures, too.
 

Ffosse

macrumors 68000
Nov 5, 2012
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My iPhone XS Max is now showing 97% and I've not used it that much since I bought it. What I mean is that I've been a light user.
 

now i see it

macrumors 601
Jan 2, 2002
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My battery is 1042 days old (to be precise). When I leave my iPhone off overnight near the window and the temperature gets down into the 30s, the battery Health (as guessed by CoconutBattery) can say 45% when I boot it up the next morning when it's cold. Then when I plug it in, the "health" suddenly jumps to 85%. Then by the end of the day it says my battery health is at 96%. So it's definitely temperature dependent. Also I can shut off my phone at night with 65% charge, then start it the next morning when it's really cold and the iPhone will show 41% charge. Then when I plug it in, it will instantly jump up to 64% charge in a blink of an eye.... So that just goes to show that iOS & the battery apps really can't figure out the true state of the battery.
 
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1rottenapple

macrumors 68020
Apr 21, 2004
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If it shuts off at 70% I would get the replaced because it really does interfere your ability to make emergency calls.
 
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T Coma

macrumors 6502
Original poster
Dec 3, 2015
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Flyover Country, USA
Do you have a Mac? If so, plug your phone into your Mac and install this: https://www.coconut-flavour.com/coconutbattery/

This will give you a pretty good idea if your phone's battery is toast or not. If you have an Apple Store around, like the others here have stated, make an appointment and see what Apple says.
My battery is 1042 days old (to be precise). When I leave my iPhone off overnight near the window and the temperature gets down into the 30s, the battery Health (as guessed by CoconutBattery) can say 45% when I boot it up the next morning when it's cold. Then when I plug it in, the "health" suddenly jumps to 85%. Then by the end of the day it says my battery health is at 96%. So it's definitely temperature dependent. Also I can shut off my phone at night with 65% charge, then start it the next morning when it's really cold and the iPhone will show 41% charge. Then when I plug it in, it will instantly jump up to 64% charge in a blink of an eye.... So that just goes to show that iOS & the battery apps really can't figure out the true state of the battery.
FWIW - Coconut shows an 84.8% capacity at 25C. ¯\_(ツ)_/¯

Cool little app though. It says my well-used iMac is 2800 days old.
 
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T Coma

macrumors 6502
Original poster
Dec 3, 2015
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Flyover Country, USA
Update:

The battery has apparently not recovered from its minutes-long exposure to ~36°F temps. Coconut Battery says 81% capacity after 399 cycles, but the phone is generally dead now by late afternoon, with no change in use habits. I suppose it's time to schedule a visit to the local Apple store, but since I bought the phone new 539 days ago, and technically it still works, I don't imagine a free replacement is in the cards.

I was looking at Zerolemon et al. battery cases, but then the Silk credit card case won't fit. It is nice not carrying a wallet.
 

JPack

macrumors 601
Mar 27, 2017
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Update:

The battery has apparently not recovered from its minutes-long exposure to ~36°F temps. Coconut Battery says 81% capacity after 399 cycles, but the phone is generally dead now by late afternoon, with no change in use habits. I suppose it's time to schedule a visit to the local Apple store, but since I bought the phone new 539 days ago, and technically it still works, I don't imagine a free replacement is in the cards.

I was looking at Zerolemon et al. battery cases, but then the Silk credit card case won't fit. It is nice not carrying a wallet.
Seems about right, batteries degrade the moment they leave the factory. Even with few cycles, batteries lose capacity over time.
 

Whoakapi

macrumors 6502
May 26, 2010
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In general you can wear down Li-ion batteries quick due to high temperatures, not low ones. The efficiency of a battery does indeed decreases in cold weather, but it doesn't cause damage as if you left it in a hot car. Some people even recommend to store Li-ion batteries in the fridge (which introduces the issue of condensation, so don't).

I think battery quality is a lot more fluid (not being digital) and it's difficult to compare two units unless they are from same batch.