I have a Minn Kota trolling motor. I'd thought that Li-Ion batteries were too expensive, but I see that I can make them out of individual cells for a reasonable cost. The problem is, I think that they put out too much voltage. My trolling motor is straight forward, but I've made a pulse width modulator so that I can run the motor wide open, yet regulate the speed without the resistance that the motor uses to regulate speed. The Minn Kota website doesn't recommend using Li-Ion batteries, saying that the voltage is too high. If I remember correctly, I can use 6-90 V at 15 A, so I don't think that this would be a problem. As for the motor, well, who knows. A trolling motor customarily uses a deep cycle battery, which has a voltage of about 13. Li-ion cells are either 3.6 or 3.7V, so that I would have a 12V battery of 14.4 and 14.8V respectively. Everything is off warranty, so that's not an issue. Think this would be a problem? Thanks.