Xantrex and magnum energy both have AGS. You may be able to add stand alone AGS to the unit. It replaces or augments the generator control panel. They use "state of charge" SOC or battery voltage. The unit will signal the generator to start and run either until a specific SOC is reached or a certain time has elapsed.
2004 Chevrolet Silverado 3500 LT with a 2004 Jayco JayFlight 29BHS
2014 Greyhawk 31FS with a 2007 Tahoe toad
2014 Thor Palazzo 33.3 with a 2007 Tahoe toad