Why does iphone automatically turn off in cold weather?

Because when the weather is very cold, the cold environment will increase the electrolyte resistance of the mobile phone lithium battery, reduce the chemical reaction rate and generate relatively less current. The battery of the mobile phone is fully charged, but it cannot be completely released, which eventually leads to the automatic shutdown of the mobile phone.

Extended data:

The electrolyte used in the battery is an organic system. As an organic liquid, like oil, it will become sticky or even coagulate at low temperature. At this time, the activity of conductive lithium salt is greatly limited, so the charging efficiency is very low, which will lead to slow charging and insufficient charging and discharging of lithium batteries at low temperature.

When the mobile phone is used for the first time, 12 hours does not need to be charged, but it is best to fully charge and discharge for 3~5 hours. Fully charged refers to normal charging to 100%, and fully charged refers to when the mobile phone uses a low battery reminder. Because the battery has to go through the processes of liquid injection, formation, charge and discharge, capacity separation, etc. before leaving the factory, the battery is in an activated state.

Lithium ion batteries have high energy density and high average output voltage. Small self-discharge, good battery, less than 2% per month (recoverable). No memory effect. The working temperature range is -20℃ ~ 60℃. Excellent cycle performance, fast charge and discharge, charging efficiency as high as 100%.

References:

Zhongguancun Online-It turns out that they are the real culprits of the automatic shutdown of mobile phones.