Arduino boat

Hey

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:

http://ev-power.com.au/webstore/index.php/headway-40160s-15ah-cell.html

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?

iPot: motor draws 9V current,

A little bit of study is needed, I think. Volts and current (which is measured in Amps) are two very different things.

You should power the Arduino from a separate battery until such time as you know enough about the potential problems to allow you to design a system that uses the same power supply for the motors and the Arduino.

The basic problem with using a single power supply is that the motor can draw enough current to make its battery voltage fall below the level at which an Arduino will work properly. If the Arduino has a separate battery that can't happen and your project will be much easier to develop.

...R

If you have a look at the datasheet for your display it will tell you how much current is required , the backlight is the big ticket item.

Thats a hint bty.

Post the details of exactly what you are using as you did in the other thread.

Those batteries are large and expensive. If they are not properly discharged and charged, they will be ruined the first time you use them.

If you need that high capacity (and so far, you've provided no evidence that you do) use lead acid batteries instead. They are much more tolerant of mistakes.

Yes, you need a motor controller. For further advice you need to post the details about the motor that you will be using.