I have several questions about the on board chargers. Its time for a new trolling motor battery and I know that maintnance is important in making a battery last. Is the on board charger good for the battery?? Do I still have to charge my battery when I get home or does it charge the battery while the outboard is running like a cranking battery??? As you can see I know absolutely nothing about on board chargers so any help at all will be appreciated!!