Powell was speaking after seeing the Addicks held 1-1 at The Valley by struggling Rochdale - their third draw in four games. Nicky Adams gave Dale a shock 53rd-minute lead but his effort was quickly cancelled out three minutes later by Yann Kermorgant's 25-yard free-kick.
The result maintains Charlton's unbeaten home record and extends their lead at the head of affairs to seven points over second-placed Sheffield United, but the Addicks boss acknowledged his side are not firing on all cylinders at the moment.
Powell said: "We knew it would be a tough old evening for us.
Rochdale settled very well. A lot of teams are going to play the way that Rochdale and Bury did recently, where they are going to flood the midfield and defence and try and frustrate us.
"Of course when that happens it can transmit itself to the players that there is a bit of edginess because we haven't scored. But we still need to keep probing and keep believing in ourselves.
"Sometimes you look at it and it is a point gained or two points dropped. It is a bit of both really because the players showed some good character to come back so soon after going down to a real scrappy goal."
