The REDARC Smart Start(R) Battery Isolator is a microprocessor controlled battery isolator used in a dual battery system. It is designed to be used in dual battery systems as a solenoid priority system to protect the start battery from excessive discharge. The Battery Isolator provides 12 Volt DC incorporating 100 Ampere of continuous ratings. The dual sensing model is used to isolate the start and auxiliary batteries in a system where the auxiliary battery may also be charged by an external source such as Solar panels or an external AC battery charger. The Battery Isolator also allows the start battery to be charged by the external source once the auxiliary battery reaches 13.2 Volts. This is useful to top up the start battery. The Smart Start Battery Isolator 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.