Victron Energy Buck-Boost DC-DC Converter - 50A One Size. The Buck-Boost DC-DC Converter is a DC-DC converter for charging a 12/24V service battery in vehicles with an intelligent dynamo. Since when the engine is running these dynamos (powered by the on-board electronics of Euro 5 and 6 engines) do not always emit the correct charging current a DC-DC converter is essential for charging the service battery properly. Please contact your dealer for any returns repairs or support issues related to this product. Package Contents: Victron Energy Buck-Boost DC-DC Converter - 50A Victron Energy ORI303050000: Buck-Boost DC-DC Converter - 50A One Size