on 16 october 2009 it was announced that mooney would be joining league one side charlton athletic on an emergency loan until 1 december. he made his first team debut the next day, coming on as a late substitute in charlton's 2–1 victory against huddersfield town at the valley. after two more appearances as a substitute, mooney was handed his first league start for the club against mk dons at the valley on 14 november, and scored an equalising goal in the 13th minute to set the addicks on their way to a 5–1 victory over their promotion rivals. he opened his side's account again in a 4–2 home win over bristol rovers on 24 november, prompting charlton manager phil parkinson to extend mooney's loan deal with the club for another four weeks, until 28 december.