Universal Battery/device temperature no longer available to apps?

[bogdanw]

It’s summer, sometimes my iPhone SE 2 (iOS 16.6) gets hot and I would like to know how hot.
All the apps I’ve tried just say “nominal”, not the temperature.
This ZDNET article “So, how exactly do you tell how hot your iPhone is?” (July 19, 2022)https://www.zdnet.com/article/so-how-exactly-do-you-tell-how-hot-your-iphone-is/ recommends Battery and charger test https://apps.apple.com/app/battery-and-charger-test/id1442110910 but the app always displays 26 degrees Celsius.

So far, the only way to tell the temperature of the iPhone’s battery is to connect it to a Mac and read it from coconutBattery https://www.coconut-flavour.com/coconutbattery/

Are there any apps for iOS that can tell the temperature of the battery/device in degrees?
Has Apple restricted this information and making such apps is no longer possible?

 

[bogdanw]

The summer is over, maybe I’ll get a definitive answer until next summer

From what I could find in Apple’s documentation and old utilities, battery temperature was available 7 years ago, but it’s no longer readable through the same API.
UIDeviceListener
https://github.com/eldade/UIDeviceListener
“What kind of power data can I get? ...Current battery temperature”
UIDevice.BatteryState
https://developer.apple.com/documentation/uikit/uidevice/batterystate
ProcessInfo.ThermalState: nominal, case fair, case serious, case critical
https://developer.apple.com/documentation/foundation/processinfo/thermalstate

Maybe a developer could offer some clarifications on how coconutBattery is getting the temperature of the battery.