we sell this for hardwire purposes, for situations where you don't want to use the cigarette plug and want to have a neat install etc, it should still be wired to a switched circuit (unless you use the vehicle all the time), the 11.6v cutoff is just a safety thing, it's not like a battery discharge prevention device where you will want to set different voltages depending on vehicle type, if you wanted something for permanent power use you'd be better off with the Multi Safer or similar where you can choose the cutoff point you need