The battery health level displayed by the iPhone XR is actually the ratio calculated by the resistance and sensor values ​​on the motherboard, and it actually only acts as a "placebo". But since the battery health does not show the expected continuous use time or more realistic data, it is more likely to be caused by the panic caused by the unknown.

In fact, there are large variables in the results calculated by the sensor, in which the temperature has a huge impact on the current. When the official after-sales service is testing the battery, it is often necessary to use professional diversion diagnostic tools, HDI tools and battery testing boards for diagnosis. It is also necessary to observe the actual packaging status, cable arrangement, appearance structure, and back glue of the battery.

In addition, in some countries and many places, the temperature is low, and the performance of the battery is constantly attenuated at low temperature, which is determined by the chemical properties of all batteries. In this temperature environment, it is normal for the battery to charge slowly and to have battery life problems.