MINN KOTA Dual Bank MK 2 DC Alternator Charger charges one trolling battery by taking the excess power from your outboard's alternator and delivering it to your trolling motor batteries to extend run times. LED indicators Red = check connection Green = alternator power on Yellow = charging trolling batteries Turns off when engine not in use Low profile extruded aluminum enclosure Waterproof and corrosion resistantDecreases on shore charge timesIncreases battery life FCC compliant