A method for controlling a battery-powered power supply. The method includes generating a first output from a first power supply within the battery-powered power supply. The first output is coupled to an output bus. The method further includes monitoring a voltage of the output bus, and determining, using a controller of the battery-powered power supply, whether the voltage of the output bus is less than a first predetermined level. The method further includes deactivating the first power supply in response to determining that the voltage of the output bus is below the first predetermined level, and generating a second output from a second power supply within the battery-powered power supply. The second output is configured to be coupled to the output bus. The second power supply has a higher output rating than the first power supply.