I would call tech support for which ever brand and model trolling motor you have and ask them if you can use a Lithium battery. When I called Minn Kota about using a single 24 volt Li Ion for my Terrova I was told not to use it at the max speed for any length of time. The Terrova is designed to operate with a reducing charge over a long period. The Li Ion batteries give 100% power until there is nothing left and will burn out the motor if at max speed, but it would be ok at a lower set speed when I am not drawing max power. (Hope this helps.)