Gillingham rarely posed any kind of a threat, and the Addicks could have won by a wider margin.
Team wise, Lee Bowyer made four changes to the team that thumped Scunthorpe on Monday.
George Lapslie, Jason Pearce, Darren Pratley and Jonny Williams returned to the starting line-up at the expense of Albie Morgan and Ben Reeves, who dropped to the bench, and Patrick Bauer and Lyle Taylor who were injured.
Anfernee Dijksteel joined Pearce and Naby Sarr in central defence, with Lapslie and Ben Purrington operating as wing-backs behind the normal diamond midfield. Igor Vetokele was the lone striker.
Two first-half goals were enough to settle the match. Midway through the opening period, Ben Purrington put in a delicious ball from the left for Joe Aribo to turn home.
Three minutes before the interval, Josh Cullen doubled the lead with his first goal for the club. Tomas Holy parried a Williams shot, but Cullen was on hand to steer the ball home.
Sarr rattled the bar, and after the interval Purrington came desperately close to opening his Addicks account.
Charlton managed the match after the break, and Bowyer will be relieved that his team completed the game without picking up any further injuries. Here are his post match thoughts:
“I’m over the moon with today. I thought it was a really professional away performance. I thought they didn’t really cause us many problems.
“I thought the back three were solid out of possession and just mopped everything up and we moved the ball when we won the ball back.
“With two midfielders scoring, that is good for us and to be honest I think we could have scored a few more if we’d have taken care, it could have been four or five.
“Everyone is working hard back to front. Igor today I thought was very good. His workrate against two defenders.
“It starts from the front when you are defending. We’re in a good place. We’ve got one more game to go in the league and I think we’re in a good place ready for the play-offs.”
Bowyer went on to explain that the injuries to Patrick Bauer and Lyle Taylor – who was in the crowd – were not serious:
“It’s precautionary. Obviously they’ve not trained all week.
“Lyle said his groin felt a bit better yesterday, and so did Pat with his knee, but it’s not gaining anything by risking them.
“I’ve got to look at the bigger picture and that gives opportunities for others to come in, stake a claim and show that I can trust them when we do get to the play-offs.”
Charlton: Phillips; Lapslie (Morgan 86), Dijksteel, Pearce, Sarr, Purrington; Cullen, Pratley, Aribo, Williams (Parker, 78); Vetokele
Subs (not used): Maynard-Brewer, Page, Forster-Caskey, Morgan, Doughty, Reeves.
Goals: Aribo 24, Cullen 42.
Booked: Pratley 45 (foul), Cullen 81 ( foul).
Gillingham: Holy; O’Neill, Ehmer, Ogilvie, Fuller; Byrne, Lopes, Charles-Cook (Parrett 65), List (Rees 71); Campbell (Eaves 46), Hanlan.
Subs (not used): Hadler, Garmston, Lacey, Oldaker.
Booked: O’Neill 18 (foul), Ogilvie 83 (foul).
Referee: Lee Swabey (Devon).
Attn: 8,047 (2,306 Charlton).