Help modifying a diy capacity tester to work with series cells

Ive built a large amount of these diy 3x 18650 capacity testers I found on Instructables. They work great. Pcb Design and code had no problems.

Ive been looking for a simple diy load tester to use with 2s-7s battery packs, when it dawned on me that maybe I could Simply modify One of these capacity testers....

Im not good with programming but the arduino code seems like it should work without much modification... Besides setting the appropriate cut off voltage the only other problem that I see is the voltage dividers on A0, A1, A2 would have to be changed.

basically my first question is what resistor values would I need to use for the voltage dividers in order to use higher voltage batteries and if anything in the code also have to be changed? ideally I would like to be able to test 2's batteries in one slot, 4s in another and 7s in the third. not all at once but have it set up so if I want to test a 2s or 4S or 7s I would attach it to the appropriate spot.

so if someone could please advise me only appropriate resistor values for the voltage dividers and if anything in the code needs to be modified for this to work I would greatly appreciate it.

Thank You

below I have attached the schematic and code for the Arduino
well I guess I can't post the code for the Arduino because it's longer than 9000 characters. So here is a link to paste bin.
https://pastebin.pl/view/b910326f