Trolling Motors and battery usage

hello to all. Myself and a friend recently purchased a well maintained 19' aluminum starcraft boat with an inboard/outboard motor. Unfortunately the motor is a bit too stout i think even with the trim all the way up for trolling. A friend loaned us a 50lb thrust minn-kota trolling motor that we hooked up to a 12 volt battery. The problem is the 50lbs of thrust wasn't enough, and we seemed to drain the battery in close to only 1-2 hours. I was going to go up to a Maxxum 70 or 80 thrust motor which should be sufficient, but requires a 24 volt battery. Does anyone have any recommendations on the motor type or battery type? What's the expected time that one can get out of the trolling motor of this type? We generally are on the lake trolling from anywhere from 6-8 hours, if not a full day. Will we require multiple batteries? If so how many...generally what do you kind folks recommend trying? I looked into gas powered motors...but i'll be honest i don't want to make the same mistake on too small of a motor and the gas ones are never described in lbs of thrust like the electric. Any and all help would greatly be appreciated. Thank you.

Re: Trolling Motors and battery usage

Gas kickers are rated in HP and electric in maximum thrust so there is no direct comparison, nor should there be. They are two different power sources. You also didn't mention how big this I/O powered boat is and what it weighs. As for electric trollers, 55# thrust motors are at the very top of the 12V power range. Anything more than that will require 24 volts. Batteries store electricity and there are many sizes (both physically and capacity). For a trolling motor you need the very largest capacity "deep cycle" batteries you have room for and can afford. Group 27 (physical size) and a battery with at least 180 minutes reserve capacity @23A draw is an absolute mininum in my view. You should also buy a motor that has Maximizer (MinnKota) terminology that maximizes run time when operating at less than full speed. Trollers mounted on the bow are far more effective than either gas or electric on the stern. Gas kickers are available in four stroke technology and on a larger boat are a better choice than electric and more cost effective and less weight. Two large batteries, an on board charger, and the motor itself adds a lot of weight. A 6, 7.5, 8, or 9.9 HP gas outboard will troll very well on most heavy boats.

Re: Trolling Motors and battery usage

First of all; what type of water are you fishing and what are you fishing for?
If trolling open water such as the Great Lakes for Salmon/Trout or Walleye then get a gas kicker. If you are fishing structure on a smaller body of water for walleye, bass, pike and musky get a 24 volt bow mount trolling motor if you boat will allow it's use. i.e. CC or open bow F&S.
If you are looking to fish these species and need an electric you could go with a stern mounted electric but boat control will not be good. In this case I would suggest getting the proper boat for the job. You wouldn't use a 9 iron to play hockey with, would you.