Connect two 12V batteries to the one charging circuit. The primary battery is for vehicle operation. The Auxiliary battery is for your equipment, the primary battery is always in the charging circuit. Only when it reaches 13.2V will the auxiliary battery be connected into the charge.

The auxiliary battery is disconnected from the primary battery if the primary battery falls below 11.4V. This protects you from two flat batteries!

Microprocessor control - improved reliability, stability and life expectancy
Effective current limiting to protect vehicle electrical system from overload
Galvanic insulation between positive main and auxiliary terminals
No damage with short surges up to 60V or main connections inverted
Delay of 2 seconds to connect when enabled
No delay to connect once enabled or to disconnect if disabled
Voltage dip protection via 2 second delay
Accuracy better than 0.5% or 50mV