REDARC 20A In-Vehicle DC Battery Charger (Ignition Control)The REDARC BCDC1220 IGN is a multi stage DC to DC dual battery charger designed for vehicles with an ECU controlled variable voltage alternator. It operates within a range of 9 32V and supports charging from both 12V and 24V vehicle systems. This charger features a lower voltage setting, allowing it to function with low input voltage from the alternator. If the voltage drops too low, it acts as a dual battery isolator to protect the start battery.