my phone stops charging at 80 percent . i have a 8 plus . any advice or tips om how to stop that ?

How are you charging your phone? Apple supplied charging cord and puck or QI charger?

If you haven't rebooted your phone do so:

Press and quickly release the volume up button

Press and quickly release the volume down button

Press and continuously hold the power button until you see the Apple Logo (keep holding past the swipe to shut down)

If your phone continues to not charge past 80%, it's still under warranty. Schedule an appointment at your Apple Store Genius Bar for evaluation. If your phone is defective, it will be replaced.

The charger is the box that plugs into the wall, the other item is the cable. The iPhone will charge quickly to 80% and then go into trickle mode. If yours is not doing this you might want to try a different charger.

Are you sure it stops? Which charger are you using?

How about power adapter?

Actually the part that goes in the wall is the power supply for the charger which is in the phone itself. Same net effect though.