I'm looking at using a 12V LDO with a 1-2V falloff, so if a vehicle is running the alternator overcomes the 1-2V falloff and the device circuit becomes powered, but I know that I don't know what then happens at 12.4V (nominal battery charge).
I don't know if it continues to supply some unsteady voltage and drain the battery or does it act as an immediate hard power kill.
Is there a better solution to the problem?