1. Loose battery connection and poor contact lead to battery capacity consumption. You can check whether the battery connection is loose.
2. The mobile phone battery has reached its service life, and the aging of the battery leads to a small amount of storage, and the battery capacity suddenly drops rapidly.
3. Too low or too high temperature will affect the battery. The lithium battery used in iPhone will be unstable in high and low temperature environment, so try to avoid using mobile phone in high and low temperature environment.