"At the same stage (last year), I was very very concerned. All our warm-up games had been poor," the Frenchman said in an interview.
"I think we are better than last year at the same stage. But look what happened then: we had nothing to show for ourselves and we won the tournament."
"I am lucky to have such a squad," said Renard, who was appointed as Zambia coach just a few weeks before the 2012 Nations Cup.
"In one year, there has been no problem. Not a player showing up late for a training camp, no behaviour problem. Maybe I have something to do with it? You have to be very tough with them sometimes," he explained.
Zambia start their campaign on Monday with a Group C game against Ethiopia and Renard would not call his squad favourite in the Jan. 19 - February 10 tournament in South Africa.
"We can't hide, we are the defending champions," Renard said.
"But we can't say we are the favourites. Everybody would laugh if I said that. Ivory Coast and Ghana are the favourites."
Zambia's build-up included a 2-0 friendly defeat by Angola and a goalless draw against Morocco.
"The game against Angola was a last-minute friendly. We were in the same hotel and scheduled the game one day before only, with all 23 players being fielded at some point. Against Morocco we played well but we just lacked efficiency," said Renard.
Renard felt teams such as Ivory Coast and Ghana would be eager to make up for their past failures having not won the title since 1992 and 1996 respectively.
With a number of talented players in the squad, Zambia, however, would be one of the teams to beat, he said.
"European clubs have been looking more closely at our players," said Renard.
"Emmanuel Mayuka has joined Southampton last summer. And Stoppila Sunzu, who is not far from being the best African centre back with Olympique Marseille's Nicolas Nkoulou (of Cameroon), is about to join Reading. And there will be others.
"Sunzu is going to be a great player and some clubs will maybe regret having overlooked him," he added.