How many batteries?

[Lunkers0]

I have a 16 ft aluminum v hull and I have a 40Lb thrust Minnkota trolling motor.  How many batteries should I have for my trolling motor?  I usually fish lakes but I want to start fishing on the Mississippi River and on an electric motor only lake this year.  I have heard that the current effects the battery.  

[JT Bagwell]

I am sure your trolling motor is only on a 12V system. But, if you

have the room, I would put an extra battery in the boat just in case.

JT Bagwell

[Muddpuppy]

 I have a 50 lb. on my boat and normally carry a spare battery.  I haven't run it on a river or anywhere with heavy currents yet, just on area lakes.  From what I have seen crossing the Mississippi there are times the current looked mighty strong.  

 In heavy winds with rough water I have seen one of mine and others get pretty weak when running mostly on the higher settings.  I know I have had to swap out a time or two, but some of those times might have been do to an older battery or not being fully charged to begin with on some trips.  I believe the operating time chart gives about 1.5 hrs. for mine on high.  I don't think I would want to risk running that river with only one battery and no other motor for back up on an all day trip.

[NBR]

River current doesn't affect battery life but pushing your boat agaist river current draws more power. You can wire two batteries in parrallel (+ to +)and increase the length of time you have suitable power. If you have a 12 volt system do not wire the batteries in series (+ to -) because that doubles the voltage and will fry your TM.

Adding batteries adds a lot of weight so be sure you stay under your boats total weight limits for safety.