Mandela Egbo has completed a permanent move to Sky Bet League Two side Colchester United for an undisclosed fee.
The 25-year-old defender joined the Addicks in June 2022 and went on to make 15 appearances for the club in all competitions.
Manager Dean Holden said: "Manny joined the club last summer with Ben Garner and was unlucky with injuries last season. He's come back ready to go this season. With the development of Nathan Asiimwe, we can't promise him the regular football he wants and he's got the opportunity to go and play regularly with a coach that he's known for many years.
"The move is a good one for him and frees up space for us as we continue to look at options to improve our squad. Manny is a fantastic character and goes with the best wishes of everyone at the club."