Large trucks, airplanes, boats and utility vehicles usually consist of two or more batteries that function independently when powering the 12 or 24 V consumers. These batteries require independent charging with reliable battery isolators or battery combiners. A battery isolator’s primary purpose is to ensure that the failure of a single battery will not incapacitate an entire electrical system. A battery isolator separates multiple batteries from one another to ensure that a vehicle has access to a backup power source. In addition, a battery isolator ensures that a vehicle's electrical system does not pull power from multiple batteries at the same time, which would rapidly drain all the batteries and cause the electrical system to fail. Del City offers battery isolators from ProMariner in 40 & 90 AMP and Mastervolt in 70 AMP & 130 AMP models to help in your onboard electrical needs.