DC-DC converter to charge a 12/24V service battery in vehicles with an intelligent alternator. The DC-DC Buck-Boost converter is a DC-DC converter designed to charge a 12/24V service battery in vehicles equipped with an intelligent alternator. Since, when the engine is running, these alternators (powered by the onboard electronics of Euro 5 and 6 engines) do not always provide the correct charging current, a DC-DC converter is essential to properly charge the service battery.