There is a wealth of information on the web sites for Minnkota and MotorGuide trolling motors. Forget trying to "make" a trolling motor. Buy one and save yourself the frustration of working with inefficient motors and controls. As for what power you need -- that determines what type and how big your boat is. 30# would be fine on a small 10, 12, 14 foot row boat. 45 - 55# on aluminum boats up to 16 - 17 feet. Up to 55# thrust requires a single 12 volt deep cycle battery (group size 24 absolute minimum). If you have a bigger boat you need a motor with even more thrust (70 - 80#). These are 24 volt motors which require two 12 volt deep cycle batteries wired in series.
