This situation may be a problem with the charging control circuit on the phone, so the power is getting less and less. In this case, it is generally necessary to send the after-sales service office for motherboard level repair or replacement of the motherboard.
advice
1. Replace the charging plug.
2. When charging, if the phone is equipped with a third-party plug-in such as charging doctor, it is recommended to uninstall and test.
3. Check whether there are foreign objects in the charging interface of the mobile phone, such as liquid intake and debris, which lead to slow charging caused by poor contact between the charging interface and the charger. If this is the case, it is recommended to send for repair as soon as possible.
4. Back up the phone data (phone book, SMS, pictures, etc.) and restore the phone to factory Settings.
If the problem persists, it is recommended that you bring the purchase invoice, repair card, and send the phone and charger to the local mobile phone repair center for testing and repair.