Deep Discharge Protection for 12 V Batteries

For load currents up to 4 A the author has used a bistable relay to disconnect the load on a 12 V battery to avoid deep-discharge. How can we provide the same function at higher levels of load current? The solution here is to use a P-channel HEXFET power MOSFET as a semiconductor relay to disconnect the load. The very low RDS(ON) of these devices is not much greater than a relay’s contact resistance.