A method for controlling delivery of electric power between a power source and an electric turning machine (ETM) comprises applying a start signal to a start-up power electronic switch to cause turning on of the start-up power electronic switch and to allow delivery of electric power from the power source to the ETM via the start-up power electronic switch. A recharge signal is applied to a run-time power electronic switch to cause turning on of the run-time power electronic switch for delivery of electric power from the ETM to the power source via the run-time power electronic switch. A circuit comprises a discharging circuit including the start-up power electronic switch for delivering the electric power when the start-up power electronic switch is turned on. A charging circuit includes the run-time power electronic switch for delivering the electric power when the run-time power electronic switch is turned on.