So, I obviously had it hooked up wrong.

So whether you run a 70 lbs thrust trolling motor off of 1 or 2 batteries you still get your 70 lbs thrust. There is no power difference between running it 12or 24v? The only difference is how long the battery will hold up before needing a charge.

Basically I can keep doing what I've been doing and when one battery dies, just switch to a freshly charged one.

Am I understanding this correctly?

Thanks for the input