A method of controlling a battery-powered remote controller to decrease a duty cycle to allow continued operations despite the quantity of the battery is bad determines a drop in voltage of the battery in standby mode as voltage of the battery is being read. When receiving a command to activate a voice function, determining whether the drop in voltage in standby mode is greater than or equal to a preset value. If yes, the method then determines whether the drop in voltage falls in a preset range. If yes, the method regulates a duty cycle of the pulse signal activating the voice function, and activates the voice function as required. A remote controller and a non-transitory storage medium are also provided.