Automatic Generator start with loss shoreline electrical

I have Magnum AGS-S on my generator. It does not start generator if shore power is lost. It has 2 settings that are set. One sets temperature that generator will start when inside temperature exceeds a setting. Mine is set at 80°. The other setting is set for starting generator when battery voltage is below 12 VDC.
I have used it when boondocking and when we leave our dog in MH as a safety when it is warm out and shore power could fail.
I purchased mine off EBAY for a good price. Many places sell it for about $250.