Power supply and method for supplying power. One example power supply includes a first power source, a second power source, and a control circuit. The first power source provides electrical current to a first power output terminal. The first power source also provides electrical current to a second power output terminal. The second power source has a voltage level that is lower than the first power source. The control circuit is configured to measure a load current supplied to the second power output terminal. The control circuit is also configured to compare the measured load current to a threshold. Responsive to detecting the measured load current being higher than the threshold, the control circuit is configured to connect the second power source to the second power output terminal to provide electrical current thereto.