Sorry Fain but that is not how the counter works. It just keeps track of the pages flipped from the moment you reset it. What you describe is not possible because the reader's battery has only four stages. If the battery in the firmware would be a variable between the number 1 and 100 or 1 and 255 I could make something based on specs.
Even if you would come up with an algorithm to estimate it still wouldn't work because you can't keep track of the hours the reader is in its "off" state. So let's say the battery went from 100% to 77% when it was not in use. The battery variable would still come with 100% and that will give you the wrong numbers considering the battery life.
