Noob help, science fair project for my kiddo

Gentlemen, I have one of those kitchen timers and I use it for a number of things. I use it as a countdown when I am exposing PCB's etch, or count up for checking capacity of batteries etc. I looked at the data sheets for AAA, AA, and N alkaline batteries and their discharge curves and estimated the discharge using the lamps for discharge. I understood the starter of this thread wanted a simple way to do it with radio shack parts.
As a side note a number of years ago I did compare 3 manufactures AA alkaline batteries for capacity. They were duracell, eveready and panasonic. The looser was panasonic. Duracell and eveready were esentially equal.

Here is a schematic of the circuit needed to log the test batteries voltage to a computer
It is all very simple for this project.
The switch and led are optional extras.
The voltage reg is needed to set a fixed reference for the ADC readings.
1 to 3 batteries can be tested at the same time.

Pete.