I am collecting parts for my boat build and an on board battery charger is on that list. I will have two 12v batteries for a 24 volt troling motor and one 12v battery for the other electronics such as lights, fishfinder, bilge, livewell. I want the charger to charge all three batteries. What type of charger will I need to get. I assume it will be a 12 volt 3 bank charger. Is this correct.