Senses low battery voltage and automatically disconnects devices to save power for starting or to preserve battery life A dead battery is one of the most common reasons for a tow. Don't get stranded with a dead battery. The m-LVD senses low battery voltage and automatically disconnects non-essential devices to save power for starting or to preserve battery life. The m-LVD is ideal for any single battery boat or vehicle that wants to avoid getting stranded with a dead battery.