[roline]

If an isolator is not used, the alternator could be connected to the common on the 1 2 battery switch. Power usage and potential alternator charge would go to the chosen battery, or both. A zap stop diode should be added to the alternator to prevent swirching to an open circuit condition that can blow the alternators diodes. Some older 1 2 battery switches may not be make before break and go open for a brief moment...