I have a Deep Cycle 24V marine battery for craking, running the boat, etc. I just bout a 2nd battery for my trolling motor. I want to be able to put a charge on that 2nd battery while I am running the motor (cruising, finding new spots, etc). How can this be done?

Thanks in advance!
So basically just run a cable from positive on batt1 to positive on batt2 and same with negative as well?

Hook them up in a parallel circuit.