From what I've been able to tell, plugging the phone in helps in some cases but there are a lot of cases where it does not help. (That's from reading around on

From what I've been able to tell, plugging the phone in helps in some cases but there are a lot of cases where it does not help. (That's from reading around on the internets. I only have direct knowledge of my own situation, where plugging my phone in did not help but replacing the battery did.)