Strange iPhone charging behavior (on both of our phones)

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Jan 7, 2009
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Rochester, MI, US, World
My wife and I both have iPhones. Me a 13 Pro, her an 11. We recently went on a long road trip, almost 23 hours one way. The strange thing was, neither of our phones would charge past a certain point during the whole trip, using either a plug-in charger brick or the Ford Sync usb cable connection. I initially plugged my phone it at 95%, and although the charging icon lit up, the phone slowly lost like 5% over the next few hours. The same pattern happened whether I used the Sync cable or the plug-in charger. So I let my phone drain using Maps over the next few hours so that the battery got relatively low. I plugged it back it, and it soon reached 88% and held there the remainder of the drive; many hours. Her phone did the same, but stuck at 84%. Any idea why? Both cables and chargers are good and capable of adding % to our phones even under heavy use, and both phones will take a full charge on any type of charging (5w, wireless, PD charging etc).

The only thing I can assume is that the phones were trying to maintain a less-than-full SOC on both, since location services made them know we were moving. Almost a sort of battery conditioning measure? I know it wasn’t the “optimized charging” as that doesn’t work when you are away from home until it learns that routine. Even if it were, that holds the battery percentage right around 80.

Whatever the reason, it was annoying. I use my phone for Maps the entire drive so I like to just keep it plugged in so that it’s fully charged when we arrive, or in case something happens during the drive.
 
In settings, Battery, Battery health and Charging, de-select optimized battery charging and clean energy charging when you need to full charge.

The "optimized battery charging" will limit charging in an attempt at improving battery longevity. I have a 1.5 year old phone and the battery is down to a claimed 86% (really it's much worse than that). The "optimize setting" did not seem to help, as my other phones have the same battery degradation.
 
In settings, Battery, Battery health and Charging, de-select optimized battery charging and clean energy charging when you need to full charge.

The "optimized battery charging" will limit charging in an attempt at improving battery longevity. I have a 1.5 year old phone and the battery is down to a claimed 86% (really it's much worse than that). The "optimize setting" did not seem to help, as my other phones have the same battery degradation.

In reality, the optimized battery charging setting should not cause what happened to us. This optimized charging happens when you sleep after it has learned your habits in a certain location(s). When on the road, especially during the day, this should not apply.
 
It's probably the USB port on the infotainment system. Those ports don't supply enough current to charge the iPhone battery while running intensive applications

iPhones have 3 typical charging rates. Power Delivery (20W), 5V @ 2Amps and 5V @ 1A. Power Delivery charging is only relevant during the first 50% of the charge. After that, the iPhone charges at a slower rate.

In order to use your iPhone and have the battery charge, newer iPhones need at least a 5V 2A charger. Most infotainment systems supply just 5V at 1A or less.

Also, some car chargers have multiple ports, but split current capacity when multiple devices are connected to it. For example one charger I have has 2 USB A ports and can supply up to 2.4A at 5V. But if you connect two phones to it, each phone will just get 5V @ 1A. Which can cause the issues above.

Finally if the iPhone is hot from being in direct sunlight, it will also pause charging. Make sure the phone isn't in front of a heater vent or in direct sunlight.
 
In reality, the optimized battery charging setting should not cause what happened to us. This optimized charging happens when you sleep after it has learned your habits in a certain location(s). When on the road, especially during the day, this should not apply.

I understand your thinking. However, I'm not sure I understand the phone's thinking :)

My guess is that the phone knows it's plugged in and does not need to charge, but that's a guess.
 
Automobile USB outlets will have various charge rates. Check your owners manual. I have done a similar pattern of plugging the iPhone in during a longer drive. The charge rate is definitely slower than say plugging into an outlet at home.
 
The fundamental issue is that the native ports on the vehicle, eiither in isolation, or totality, probably lacked enough power capacity to charge the phones, especially if they were being actively used in a demanding fashion, like providing GPS navigation or streaming content. The OEMs have either never prioritized telematics and/or haven't been great at it, so it's not unexpected.

Passthough situations, or shallow, repeated piecemeal charging sessions can also throw the power management system out of whack, causing issues with getting an accurate reading even when connected to a relaible source like a wall power adapter. The solution to that is to reboot the device, which should get things back in sync, or if that fails, a hard reboot.

The Optimized Charging feature is a charge-to-80-and-finish-when-expected management strategy based on repeated usage patterns, and unlikely to have played a factor here. Good in theory, but even those who make use of it can find it doesn't always reliably function. IMO, it's overwrought, inflexible, tries to be clever, but is too dumb to actually work well.

iOS does a have a mininum power threshold where it will display "Not Charging" instead of the lightning bolt, but it's a small figure.

Apple shipped iPhones with their venerable 5W sugar-cube adapter in the box up through the XS, until it decided not to include one at all in most markets, suggesting users buy their newer 18W adapter, or a third-party adapter.

So iDevices will happily charge, albeit more slowly, with lower capacity adapters, albeit more slowly, and if in active use, the total consumption doesn't exceed the supply capacity of the source being used. The iPads Pro, which were their first devices to adopt Type-C and PD, relies primarily on PD, but will fall back to BC, and have no issues charging at ~7.5W, despite having batteries twice as large as the phones, and shipping with 18W, then 20W adapters. The lower level sources will require more time, but present no functional issues.

PD is on a different level than earlier charging protocols, not only providing up to 240W in the latest spec, but also being fundamentally a bi-directional protocol that actively negotiates power levels between the source and the sink. What a source may offer, what the sink asks for, and what they agree upon is subject to different factors, so it would not be accurate to box them into specific levels. A device may choose one power profile with one source, and another profile with a different source, also keeping in mind that the two sources may not necessarily support exactly the same profile options, so it also adaptable in nature.

But basically, it comes down to supply and demand.
 
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Apple shipped iPhones with their venerable 5W sugar-cube adapter in the box up through the XS, until it decided not to include one at all in most markets, suggesting users buy their newer 18W adapter, or a third-party adapter.


A lot of iPhone buyers already had the cube so it was an opportunity to reduce duplication. I have 4 or 5 around the house myself. Another factor is that more and more people are using charging pads.
 
A lot of iPhone buyers already had the cube so it was an opportunity to reduce duplication. I have 4 or 5 around the house myself. Another factor is that more and more people are using charging pads.

True, and I have no desire to wallow in the "Hollow Green Marketing Justification" or "They're just being cheap and greedy" arguments that consumed that decision.

I only wanted to point out that the more recent, and modern class of iPhones have no charging issues with a 5W adapter, and something with higher capacity isn't a necessity if there is no time crunch, or need for higher rates. And gentler charging is less stressful on batteries.
 
iPhones have no charging issues with a 5W adapter, and something with higher capacity isn't a necessity if there is no time crunch, or need for higher rates. And gentler charging is less stressful on batteries.
I just bought a 45W charger for my iPhone. I want to make sure when I trade it in every 2 years (work phone) that nobody will ever get it as a refurb. I usually go thru 2-3 battery cases over those 2 years as well. I need an iPhone with the battery life of an iPad Pro.
 
I just bought a 45W charger for my iPhone. I want to make sure when I trade it in every 2 years (work phone) that nobody will ever get it as a refurb. I usually go thru 2-3 battery cases over those 2 years as well. I need an iPhone with the battery life of an iPad Pro.

Apple refurbs get new batteries and outer casings in the the normal course of the refurbishment process.

In testing, the 14 Pro draws a peak of 26-27W with most adapters (including one rated at 140W), with the exception of an older 29W Macbook adapter, likely due to the limited number of profiles it supports. Even then, that peak is <30W.
 
Most likely it’s the battery optimization, which is turned on by default.
I also noticed that when the phone is hot, from high screen brightness like during using google maps, the charging may slow down or stop.

It’s all apple programming in one way or another.


All the posts about the usbs lacking power are funny, if the port can charge the phone fine up to 80% or so, it will certainly have enough power to charge it to 100% because that last bit is done at a slower rate, requiring less power draw.
 
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