Battery size for an electric trolling motor

Question
Richard,
1.Which battery size you suggest for my Sears 12v electric trolling motor?
No idea of how much thrust. 2 Blades, has reverse and fwd motion, Hi and Lo Pwr positions.
2.And how big can the boat be?
I live in south Chile and we can do a lot of fishing around here. (The angler's paradise, by the way).I want to put this motor to work.
Thanks and best regards.
Cristian Larrain.
Osorno, Chile

Answer
Hi Cristian;
 I really cannot say based on the information you have provided.  Try using the computer to get in touch with Sears and see if you can get the specifications for you motor.  If that does not work, I suggest you check out the various electric trolling motors and batteries offered by some of the major fishing and boating supply places.  You should be able to see what similar products are on the market and the specifications as to current use and run times.  You can then find appropriate sized batteries.  The following are some on line mail order sites that I have used and found very informative:  Cabelas.com, Basspro.com, BoatUS.com, and BoatersWorld.com.  There are many more, but these should give you a good idea of what you need and what your motor should be able to do.  I hope this is of some help.
-Rich