i have an asus laptop it is fully charged but will work unless i plug charger in red light o n

[Falcon_ASUS]

@Er3 
Based on your description, it is possible that the battery is malfunctioning. We recommend that you send the laptop to a service center for further inspection.
The following is the contact information:
https://www.asus.com/support/service-center-location 

Also you can contact the local service center for help.
The following is the contact information:
https://www.asus.com/support/CallUs# 

Sorry for any inconvenience it may be caused.