The former Blues player, who played at St Andrews between 1997 and 2000 paid tribute to Steve Bruce, a former team mate of Charlton during his time at City and now manager of the Midlands side.
"They are a typical Steve Bruce team and are very good defensively. During my time at Birmingham we all knew he was going to make a good manager."
Charlton 32 yesterday, also went on to say that he feels that the Blues can go onto better things and their fan base will help them become a force in the Premiership.
"I do expect them to go on to bigger and better things. They've always had the fan base, which is bigger than Aston Villa's. Once they complete the last side of the stadium I can comfortably see them getting 38,000-plus crowds."