I have a project I need to run off batteries. I've built the AA Undershield (The Arduino AA Undershield : 6 Steps - Instructables) and it gives me the runtime I need (> 20 hours), so far so good.
I was thinking about connecting the +3v from the batteries to an analog port to measure battery life. I think this should work, but I don't know enough about hardware to make sure this isn't a bad idea.
Is there any reason I shouldn't do this?
Thanks in advance.