I did at one time own a deep cycle battery, long gone, for my trolling motor which I gave to the guys I fish with who have boats. The guy I fish with carries two deep cycle batteries in his boat, in case he drains one. The other guys use one battery. It's heavy enough it usually takes two to carry it to and from the boat. I'll see if I can find out what type they use. Generally, we usually we fish between 4 and 6 hours. The trolling motors are 50 and/or 55 lb. We do run at full speed between spots when fishing and then anchor up or drift when we fish. The first thing we do when we get back to the house is put the batteries on the chargers. One thing that impacts how long the battery will last is weather conditions. One will last longer if you're dealing with calm or low wind conditions. If you're running into a wind with chop on the water you'll use up more of the battery. Let me see if I can find anything out for you.