Depends on speed you are trying to run and how long you’re planning on trolling. When trolling under 1.5 I can use only the trolling motor and still get my 6 hours run time if not going into the wind I can go up to 2.4-2.6 with trolling motor but I’m running on a high set which will drain batteries quick. I would think if I was only going to be out for a few hours (3-4). And was only needing up to 1.6-1.8 I could do that on 1 bank of batteries on my setup with the 112 lb thrust lighter boats could do a little better. Also I’m running Walmart batteries. Maybe the better high end batteries would do better but I set up with 2 banks of batteries cheaper