Hi all,

I have been racking my brain to come up with a solution for this to no avail and searching has not been fruitful either. My task at hand is measuring the voltage of 4 different series/parallel batteries, each having 3 readings each for a total of 12 readings. I need to monitor the voltage of either cell and the cells in series of a series/parallel battery pack.

This is the battery that I am dealing with. It has 3 terminals where the left most is positive, the right most negative, and the center either the positive or negative for either side. Measuring the left terminal and the center gives the voltage of one cell, the center and the right most terminal gives the voltage of the right cell, and measuring the left and right most gives the series voltage of the two.

The series voltage isn't crucial since it can be extrapolated from the two other voltages, however, in this application, it is critical that the left and right cells of each of the 4 batteries be monitored independently and simultaneously.

Now obviously the issue here is that the ground is not consistent so simply grounding the signals together and running the positives into the analog inputs is not an option. I know I need to isolate these readings so that I can feed them into the Arduino analog inputs but I am just at a loss as to the best solution. I am thinking that a dc-dc isolated converter can be used but I have not found one that I know for sure will do the job. I'm not very familiar with onto-isolators or any isolator for that matter and I am in desperate need of some help here.

Any guidance or suggestions would be greatly appreciated! Thank you all!

-Blake