Scott McGleish headed Orient in front but the Addicks were back on terms five minutes after the restart when Paul Benson tapped home.
Bradley Wright-Phillips fired Charlton ahead and Jose Semedo`s header sealed the points - but only after Powell had given his men a half-time rocket.
He said: "You can sometimes forget how to win and of course in our last home game against Southampton I felt we put in a performance. I had a go at them because I just said they demand more here and I demanded more from them.
"As you saw as a result I think they to a man demanded more of each other, they were more concentrated, they never let Orient settle and the end result was three goals.
"We could have scored more but obviously Orient hit the bar a couple of times near the end, so it was an exciting second 45 minutes."
Source: PA
Source: PA