Smart Separator - Battery Discharge Protection

It constantly compares the voltage between the starter battery, the auxiliary battery, and their connected loads. As soon as the starter battery voltage rises (charging by the alternator), it also switches the charging power to the auxiliary battery. If the starter battery voltage drops below 12.8 volts, it disconnects the auxiliary battery from the charging process. A D+ signal is not required for this, thus reducing the wiring to a minimum. When the auxiliary battery reaches 10.5 volts, it switches off all loads to protect the battery from deep discharge.