Weird/Odd. Hot iPhone 13’s iOS v17.6 (updated from iOS v17.5.1 yesterday) battery power percentage dived from recharged 88% to 23% from 6 PM to 9:30 PM while out to eat dinner in a crowded restaurant and commute to there and back home. Battery statistics said it was hot to recharge at 88% max. Usage shows “Find My” and weak cellular using half in the background for the first hour, but after that was just “Find My”. Health shows 89% which is normal for this iPhone from 2/1/2022. It was in the purse most of the time. What’s going on? Is this a new bug or something?
Thank you for reading and hopefully answering soon. :)
It’s not uncommon for iPhones to have to do a lot of background work after an iOS update. Heat and power drain are the typical signs. And yes, sometimes when an iPhone gets hot enough it will stop charging because charging is itself an additional heat source. And if there’s one thing Li ion batteries such as those in your iPhones don’t like (premature battery aging), it’s heat, so stopping a charge if the phone’s too hot makes perfect sense.
Regarding heat and power drain, I wouldn’t think bug until I see such behavior continue well after the iOS update (say >48 hrs after).
Ah, two days. I thought it would happen earlier than that. Shouldn’t it be done if it is connected to a power plug and not on battery? It seems like a bad design to do background work on battery like that.
I’m not sure it’s just upgrade reindexing etc. - sometimes this just happens randomly to me. Force-closing an app that’s using a lot of battery usually works, but Find My is problematic to force-close, so a simple power off power on is what I’d try next.
It may have been a weird glitch; maybe your phone was connected to a lost phone or AirTag or similar and was trying to communicate when it was in poor cellular but got caught in an infinite loop of trying to communicate. Just guessing, of course. There are too few tools to be able to definitively determine a cause.
Yeah, I did a shut down and power back on overnight before recharging overnight. We’ll see what happens later. Yes, this account has its own AirTags and who knows how many non-family shared ones were near by. No lost items and iPhones. Also, no Apple Watch.
A weak cellular signal is a common cause of large battery drain, because the phone has to boost the gain on the radio in order to maintain a connection to the cell tower.
Aside from that, I concur with everyone else - heavy loads, manifesting as sluggish behavior and high battery drain, for a day or two after a software upgrade are to be expected.
So far, 13 is doing good (not hot). It capped out at 80% overnight. I am currently recharging it from 63%. Still 89% health. I wished it didn’t do the maintenance when on battery only even when idled. Apple should only do that when connected to external power.
If it waited to do all update-related indexing and clean-up only while it was charging, that would probably be worse. All that activity can make the device hot, as you noticed. That could potentially stop the charging, in which case it would either still have to do all the work while not charging (draining the battery more), or stop doing it until the device cooled down enough for charging to resume—at which point the cycle would start all over again. You’d end up with a less-charged phone, and the clean-up would take much longer.
That longer clean-up would happen for two reasons: one, the aforementioned interference with charging; and two, most people have their devices on charger for less time than off. If you assume that your phone is on charger for about eight hours a day (overnight while sleeping), that would make the process take about three times as long, in terms of raw passage of time. A process that currently takes between maybe a few hours up to two or three days would be potentially stretched out to over a week.
And your device would, during that period, be using more battery anyway, because the point of all that reindexing is to make the device more efficient, so that it uses less power for everyday activity. The process of updating the OS pretty much erases many of the existing OS indexes, so it has to start from scratch, and until it’s done that, retrieving the information that would have been in those indexes will take longer and use more power.
It might be nice to have a Settings option to pause the reindexing process, but it’s unlikely Apple will ever do that because the need for it is uncommon. Numbered OS updates don’t happen every day, every week, or even every month, and the reindexing is unnoticed by most users. It would needlessly complicate one of those things that should “just work”.
Hmm, I do remember it stopped charging at 89% because it got too hot according to its battery message and then drained battery power when out for 3.5 hours in the background in the purse.
I would agree with the “couple of days” allowance for a phone processor usage surge after an upgrade. I’d keep it plugged into power as much as possible during this time. Could also help to force quit all apps (swiping up). I would also reboot the phone.
Maybe, but that would surprise me. Remember that your phone reboots (at least once) during any OS upgrade.
And apps will not auto-restart, even if they are in your phone’s history list. They will all be in an “idle” state, where nothing is running and their state is checkpointed to the file system. They won’t start running until you bring them to the foreground (via the app history page or by tapping its icon).
Yes the phone restarts at least once as part of software installs…
But that doesn’t do anything for potential runaway processes that could be causing a hot phone / heavy battery usage. That’s why it could be helpful to restart when your phone is exhibiting the above behavior.
Yes, I agree, but force-closing apps before or after powering off is unnecessary. Powering off by definition closes all apps. The screen that you see when you swipe up halfway is not a screen showing all apps that are running - it is the multitasking screen that shows which apps you have used in reverse chronological order, which is one way to quickly switch between two apps. It does have the secondary function of force-closing apps, which really should be done only if you suspect misbehavior.