Why does the battery health drop when the mobile phone is charged?

If the "Battery Health Decline" box appears in the notification bar when your mobile phone is charging, it is because your mobile phone system has a battery health detection function. When the system detects that the battery has aged, it will remind you that the health of the battery has declined.

Solution:

With the increase of battery service time, the battery capacity will decay and age, which will lead to the decline of battery health. In order to ensure your experience, it is recommended that you back up important data in advance (third-party applications such as QQ and WeChat need to be backed up separately) and bring the purchase voucher to Huawei Customer Service Center for battery maintenance.

Related links are as follows: Huawei Customer Service Center maintenance spare parts price inquiry, consignment service and reservation service.