dHenry,
Yep, I understand that and know that MOST of the current would go thru the shunt. My concern was how much would go thru the chip and that was answered by another poster that told me that the input impedance was high enough to not concern myself with it.
So, on with the project when the Pololu device arrives. I plan on hooking the Pololu device up with my battery charger and using the Arduino to measure the charge current of a battery. That will give me a number to compare the Arduino results to as the battery charger tells me instantaneous current throughout the charge cycle. That should be a pretty good test of my circuit and code. Then I can move on and write some code that will allow me to measure unloaded voltage and loaded voltage and current so I can determine the internal resistance of the battery under test.
RWW