The result is hardly likely to have impressed the Middle East consortium said to be interested in buying the London club and the future of beleaguered Alan Pardew was thrown into further doubt.
After being battered for the first 20 minutes, Bristol City must have wondered how their victory proved to be so comfortable in the end.
Charlton paid the price for missing a hatful of early chances as they got off to a high-octane start, but once the visitors scored against the run of play in the 26th minute the confidence visibly disappeared from Pardew's team and they failed to get themselves back into contention despite three second-half substitutions.
Without their influential skipper Mark Hudson and Jose Semedo both suspended, Charlton should have been in front after 48 seconds when Luke Varney was clear in the penalty box but shot straight at goalkeeper Adriano Basso.
This pattern continued as Basso saved from Kelly Youga and Darren Ambrose, who should both have done better had they shown a little more composure.
When Andy Gray hit the post for the home side they must have realised it wouldn't be their night and they were punished on 26 minutes when Dele Adebola played in Lee Trundle, who showed the calmness that Charlton lacked by tossing the ball into the net past Nicky Weaver.
The doubts and mistakes that the West Country side made early on disappeared as they bossed the rest of the game and they would have added to the lead but for two fine saves by Weaver from Lee Johnson and Gavin Williams.
Charlton started the second half poorly and were punished again when Williams scored with a sweet left-foot strike into the top corner of the net.
With the home crowd getting restless and boos ringing around The Valley, Charlton had a couple of late attempts from substitute Chris Dickson and Varney.
But in the end City eased home to their third away win of the season and back-to-back victories which takes them back towards a play-off position.