Why my iphone stop charging ing 82percent

glessy32 wrote:

Why my iphone stop charging in 82percent

Because maintaining an iPhone battery at 100% decreases the longevity of the battery.

So Apple charges to ~80%, and only goes to a full charge shortly before you usually start using the iPhone.

You can shut off this charging behavior, but it can mean you will need to replace the battery sooner.

Details: About Optimized Battery Charging on your iPhone - Apple Support

In addition to Optimized Charging, if you fast charge the battery it will get warm, and it will stop around 80% to cool down. If you leave it connected it will eventually resume and finish the charge, but at a slower charge rate.