If you need to turn off the tone when the battery is fully charged, you can go to Settings-Applications/Applications and Permissions-Application Management-Click ":"-Display System Program-System Interface-Notification-Charging Complete/Battery Full-Sound-Select Mute. If you don't have this option, you need to mute it.
If you have more questions, you can enter vivo official website-My-Online Customer Service-Sliding Bottom-Online Customer Service-Enter Manual Customer Service and enter the consultation.