Why is it that my phone used to use up less power, and only used a few percent of it to read novels in a few classes? Now my phone is fully charged, and it's fine even if I don't touch it?

There could be many reasons for this. Here are some possible explanations: 1. Changes in mobile phone usage scenarios: In the past, mobile phones might not be as intelligent as they are now. The usage scenarios were relatively simple, such as just reading a few classes and novels. Now, with the development of smart phones, the functions are becoming more and more powerful, and the usage scenarios are becoming more and more diverse. For example, running multiple applications at the same time, watching videos, playing games, and so on. These activities will consume more power. 2. Caching and updating of applications: Some applications will buffer some data, which will take up a lot of storage space but also consume some power. Other applications may be updating in the background, and these updates may consume some power. 3. Mobile phone system update: Some mobile phone system updates may improve the performance and functions of the mobile phone, and may also reduce the power consumption of the mobile phone and increase the battery life of the mobile phone. 4. The health of the phone battery: If the battery life of the phone has aged or is seriously damaged, then even if no operation is performed, the battery may be exhausted quickly. It should be noted that the above are only some possible explanations. The specific situation may vary from person to person. If you have questions about your phone's power consumption, it is recommended to try to restart the phone to check whether the phone charging port and battery are damaged or have poor contact. You can also try to close some unnecessary applications and system updates to check whether the battery life of the phone has improved.