However, they will have to do a lot better if they are to cement their claim for a Premier League spot next season.
They were jaded until the last 25 minutes when manager Alex McLeish put on three substitutes, all of them strikers, but despite the firepower from the three new faces, they were unable to breach bottom-of-the-table Charlton's defence.
In fact it was the home side, marooned at the bottom of the table and almost certain to be relegated, who would have won the match in the dying minutes but for two great saves from Birmingham goalkeeper Maik Taylor to stop goal-bound efforts from Jonjo Shelvey and Tresor Kandol.
Seventeen-year-old Shelvey, the youngest player on the field, was once again the shining light for Charlton. He had a couple of early efforts, one which went over the bar and the other that was saved.
It was poor fare in the first half but the game livened up as it opened out in the latter stages and Birmingham, who included three former Charlton players in their squad, produced their best efforts from Kevin Phillips who saw his low shot saved by Charlton goalkeeper Rob Elliot, who also did well to keep out Keith Fahey's shot.
Charlton's Chinese international Zhi Zheng had a glorious opportunity after 74 minutes but was denied by a last-ditch defensive clearance and then Taylor produced the two saves to keep Birmingham in the game and deny Charlton their first back-to-back victories of the season.
The Addicks have won just three Championship matches out of 27 and despite the point they gained, it is virtually certain that they will be playing in the third tier of English Football next season for the first time in 28 years.