16 Volt to 12 Volt - Voltage Reducer 16 Volt to 12 Volt - Voltage Reducer. Universal 15 amp. 18/16 volt to 12 volt DC converter. This reducer allows you to connect 2 eight volt batteries to supply power to your headlights and/or stereo system. For a full bank reduction, see my 48 volt to 12 volt reducer on this website.