Glad to hear that you like your Sony cells. The smaller 18650vt cells 1100 or 1300mAh can be found in Bosch 36v powertool packs (20 cells) quite similar to dewalt 36V packs (10 A123 cells). To compensate for their voltage drop at the end and to give a more comparable power output to my 10s1p A123 packs i went up from 8s2p to 9s2p.
This is one of my last discharge graphs dating a few days ago.
As you have noticed there is no noticeable real end of discharge. Lipos and A123 drop their voltage heavily at the end. Those Sony cells dont. They are slowly getting weaker and weaker. At the end of my run at some amp spike they dropped down to 18.89V which represents only 2.09V per cell. I start at 37,8V and voltage comes down below 28V (-> 3.1V per cell) with no load. I usually finish driving when top speed becomes boring
