I made a polyester boat which I would like to supply thrust with a motor. I got my eye on these batteries and would use 3 of them to get around 9V:
Now what I am doubting about is do I need a motor controller and if the motor draws 9V current, can I still supply the Arduino board and the other electronics in the boat with electricity at the same time? If so, how do I make different output from one battery pack? Do I make a three-split wire?