Marine batteries are designed to withstand the wet environments found in boat cargo areas as well as the abuse pounding waves can deal out on a voyage. A boater might be able to get by with a battery intended for a car or other vehicle type, but that power source may suffer catastrophic failure from the extreme environments where anglers depend on their equipment. Lower output rates can mean higher amperage draws as well, which can cause damage to some marine electronics if used on a regular basis.   Anglers using a standard car battery to power a trolling motor also may find themselves wanting more capacity, as starting batteries are designed to deliver large amounts of current in short bursts, while trolling motors require lower amounts of energy spread out over a long period of time.