A system to control in real time a charge volume of an autogenous mill or a semi-autogenous mill including at least one accelerometer connected to a rotatable mill shell producing acceleration over time signals. The system includes a wireless antenna, a signal receiver module, and a modular magnetic power generator unit communicating with a master control processor connected to a network and to a distributed control system of the mill. The system has computer instructions to receive the acceleration over time signals and compare the acceleration over time signals to preset charge limits and produce commands to the distributed control system to automatically alter at least one of: speed of the rotatable mill shell, a particulate feed rate, a water feed rate, and combinations thereof when compared acceleration over time signals exceed or fall below preset charge limits.