The REDARC Smart Start(R) Battery Isolator is a microprocessor-controlled battery isolator used in dual battery systems as a solenoid priority system. It will protect the start battery from excessive discharge, whilst allowing the auxiliary battery to supply non-essential loads. Provides 12 Volt DC incorporating 100 Ampere of continuous ratings. The battery isolator is primarily used in 4WD and commercial vehicles and incorporates electronic components that will prevent the solenoid from generating high voltage transients. It is better than a diode battery isolator due to the voltage drop associated with diode type isolation.