Some DC electromechanical switches are hard to come by in today’s environment of materials shortages and shipping constraints. In contrast, solid-state switches and contactors can be easier to source and offer many advantages over traditional switches—often at the same price point.
The Waytek Blog
Fire trucks, work trucks, towing vehicles, boats, ambulances and off-road equipment do more than start their engines and move from point A to point B. Accessory components such as lights, entertainment systems, communications equipment and more are electrical loads drawing power from the battery when the engine is off. A common solution is adding an auxiliary battery to operate the additional loads, however if an auxiliary battery is simply wired into the vehicle electrical system, you will experience multi-battery drain issues. Starter batteries need to be isolated from auxiliary batteries.