There is not a simple answer to this question. I see a few answers
- From a safety point of view ... a 3s pack should never be more than .05V out of balance. This is because most chargers charge to 12.6V but not 4.2V per cell. You can get 12.6V by having (3) 4.2V cells or by having (1) 4.3V cell and (2) 4.15V cells. Charging a cell to higher than 4.3V can cause it to fail, including failing by bursting into flames.
- From a performance point of view ... the closer matched the cells, the more evenly they will discharge. So as balanced a possible would be desired. That allows for the highest, most stable voltage while discharging.
- From a longevity point of view ... the closer they are matched, the closer the voltage during and after discharge. Again as balanced a possible. That way you don't over discharge one cell more than the others. This will keep the pack in better condition.
There are other answers but these are what comes to mind right now. I would think that .023V is good but not great. Mine are usually dead on after a charge and no more than .02 after a day of rest.
Team New Mexico