Originally Posted by Roelof

2 to 3 ohm seems unlikely, it shall be in the range of 2 to 3 milli Ohm and that is normal for normal cells.

The guys discharging and chaging their batteries with 40A only do that to heat the cell from te inside, a heated cell will give a lower IR but the question is if you are that good to notice it. With a 20A discharge you will notice a longer stable voltage when charging the battery and driving it so it is wise to check how to build a resistor bank with your X6. No need to go to the max but a 15 to 20A discharge can do wonders w/o shortening the life of your battery.