The Addicks were already down to nine men when Powell went onto the pitch to protest after Gavin Williams appeared to handle the ball before tucking away Rovers' equaliser five minutes from time.
He was eventually led round the side of the pitch after being sent from the dug-out by referee Rob Lewis.
Afterwards, Powell said: "He just said I've got to go off.
"Obviously I came onto the pitch and explained that it looked like handball."
Powell was fined and banned for one match for misconduct earlier this season, but this time he has requested a personal hearing.