The present invention relates to a safety apparatus (20) for monitoring charging of an electrical energy store in a motor vehicle (100), having at least one first sensor device (21a) and at least one second sensor device (21b), which are both designed to capture motion data of the motor vehicle (100) and to provide said motion data as a sensor signal; and a control device (25) that is coupled to the at least one first sensor device (21a) and to the at least one second sensor device (21b) and that is designed to deactivate the at least one second sensor device (21b) while the electrical energy store is being charged and, if the control device (25) detects motion of the motor vehicle (100) on the basis of one of the provided sensor signals, to actuate at least one actuator device (30) of the motor vehicle (100) in order to brake the motor vehicle (100).