Flashing 1 white 1orange

Hey guys 

My laptop is flashing 1 orange and 1 white and as far as I read, this would means that there is a problem with either the battery or the charger

so, my first question would be, how do I know which one is the problem?

and extra problem that I am having is that whenever the laptop is plug in to the charger, it is faster and whenever is not plug in it is significantly slow

I really appreciated any help 

thank you very much in advance