iPhone 16 continually beeps when fully charged

Beeping like that is not normal behavior. If you have tried different cords, etc. that Lawrence indicated, then you need to have the phone checked by Apple. Since you mention is is brand new, it is covered under warranty.

Nikonninja wrote:

why does my iphone continually beep after fully charged. Have used different cords and chargers.

It’s probably broken. Have you used only Apple cords and Apple chargers? Or at least ones that are certified as MfI (Made for iPhone)?