the 5 speed motors drain the battery a heck of a lot quicker than the variable speed.....
Down in south florida while fishing the creeks and deeper flats, the sound from the clicking of the 5 speed alone would spook fish off.... Switched to a variable speed, picked up 30% more battery life, and spooked less fish when changing speeds... If you are going to get a 24V setup, get as much power as you can out of it... a 65 would be on the LOW end of the 24V.... what boat is this going on? If you can get away with a 12V 55 lb thrust, it leaves you with alot less weight ( 1 less battery) and still puts out good power....