A transport refrigeration system comprising: a transport container enclosing a refrigerated cargo space, the transport containing being integrally connected to a vehicle; a transportation refrigeration unit in operative association with the refrigerated cargo space, the transportation refrigeration unit configured to provide conditioned air to the refrigerated cargo space; an energy storage device configured to provide electrical power to the transportation refrigeration unit; an electric generation device operably connected to at least one of a wheel of the transport refrigeration system and a wheel axle of the transport refrigeration system, the electric generation device being configured to generate electrical power from at least one of the wheel and the wheel axle to charge the energy storage device when the electric generation device is activated; an inertial sensor configured to detect at least one of a deceleration of the vehicle and a downward pitch of the vehicle; and a power management module in electrical communication with at least one of the energy storage device, the electric generation device, and the inertial sensor, wherein the power management module activates the electric generation device when the inertial sensor detects at least one of the deceleration of the vehicle and the downward pitch of the vehicle, characterized in that the power management module is configured to detect a state of charge of the energy storage device and increase a torque limit of the electric generation device for a selected period of time when the state of charge is less than a selected state of charge if the transport refrigeration system is also detected to be decelerating and/or going downhill, the selected period of time being short enough, such that the electric generation device does not overheat. a transport container enclosing a refrigerated cargo space, the transport containing being integrally connected to a vehicle; a transportation refrigeration unit in operative association with the refrigerated cargo space, the transportation refrigeration unit configured to provide conditioned air to the refrigerated cargo space; an energy storage device configured to provide electrical power to the transportation refrigeration unit; an electric generation device operably connected to at least one of a wheel of the transport refrigeration system and a wheel axle of the transport refrigeration system, the electric generation device being configured to generate electrical power from at least one of the wheel and the wheel axle to charge the energy storage device when the electric generation device is activated; an inertial sensor configured to detect at least one of a deceleration of the vehicle and a downward pitch of the vehicle; and a power management module in electrical communication with at least one of the energy storage device, the electric generation device, and the inertial sensor, wherein the power management module activates the electric generation device when the inertial sensor detects at least one of the deceleration of the vehicle and the downward pitch of the vehicle, characterized in that the power management module is configured to detect a state of charge of the energy storage device and increase a torque limit of the electric generation device for a selected period of time when the state of charge is less than a selected state of charge if the transport refrigeration system is also detected to be decelerating and/or going downhill, the selected period of time being short enough, such that the electric generation device does not overheat.