Charlton was originally a 23rd round pick by the Reds in 2015 out of NJIT. After a career .851 OPS in college, Charlton hit .272 in 2015 for rookie league Billings with a.814 OPS. In just 191 at bats, Charlton had 17 doubles and five home runs. However, he was promoted to Low-A Dayton to start 2016 and he struggled. In his first 110 at bats, Charlton was hitting just .182 with 46 strikeouts before being sent back to Billings.