"I had harsh words at half time but didn't need to say anything at full time as the players knew that wasn't good enough," he said after the 3-1 defeat at The Valley.
"We didn't get going from start to finish. It never happened for us and we were beaten by a better team.
"Charlton worked harder, won more balls and overpowered us. We've had success because we worked hard collectively but we didn't do that today.
"The third goal summed us up. Andy Melville's better than that and he's very disappointed.
"That was probably our worst performance since I took on the job."