A method includes, in a mobile communication terminal that is powered by a DC-DC converter and is operated by a user in accordance with multiple possible usage scenarios, predefining for each of the possible usage scenarios a repective set of one or more parameters of operation for the DC-DC converter. When the user operates the terminal in accordance with a given usage scenario from among the possible usage scenarios, the predefined set of parameters of operation corresponding to the given usage scenario is selected, without physically sensing an electrical current drawn by the DC-DC converter. The DC-DC converter is configured to supply electrical power to the terminal using the selected parameters of operation.