No, they are all identical. I see what's going on here when you speak about flat curves and varying voltages from vendors. You are talking about loaded voltages and I agree that it is extremely unreliable to guess the SOD from a loaded voltage. I'm talking about unloaded or "resting" voltage.

The reason I brought this up was to help the OP get an indication on the SOD and if he'll use one of my charts (when resting of course) it is possible to tell the state of charge with surprising accuracy. In otherwords going from the post 1.

If user can simply measure the open voltage then the pack can be verified that it is full at 12.6 volts. If it is 11.1 then it's discharged. The TOPS of my graphs are open voltages after a rest period long enough to get a good springback and measurement. The BOTTOMS of my graphs are the part that your talking about and depending upon the load and pack can be all over the place from 1-4 volts at ANY state of charge. This is why we must rely ONLY on an open voltage reading.