I have a 2004 Minn Kota Maxxum 65/SC that has lost power under load.
I have replaced the batteries last week and took it out yesterday. It did not seem to have much power. I had to run the motor on 4 out of 5 with no wind. It still barley moved my 17.5 aluminum triton around. I checked the prop for line and found non. If I hit it when out of the water, it seems to run fine. The 3 and 4 speed appear to run real close to the same speed.
It just feels like the batteries have lost all their power when I run it but I got the same results with the new batteries as I did with the old.