The REDARC Smart Start SBI224D is primarily used in commercial vehicles to protect the start battery from excessive discharge and provides 24V DC, while incorporating 200A of continuous ratings.This dual sensing model allows charging of batteries in instances when the auxiliary battery may also be charged by an external source, such as an external AC battery charger or solar panels. When the auxiliary battery reaches 26.4V from its external source, the SBI224D will then charge the start battery as well.Additionally, the microprocessor-controlled battery isolator has power saving technology that prevents the solenoid from generating high voltage transients. It is used rather than a diode battery isolator due to the voltage drop associated with diode type isolation. Advanced fault detection warns the user of over-voltage, voltage drop, and excessive current draw conditions.If you're looking for safe way to charge auxiliary batteries and receive full surge protection, rely on the easy-to-install REDARC Smart Start SBI224D. The SBI range manages battery charge for your secondary battery banks when on the road to your next great adventure.