[dimitri]

Only 2P ? These are 10AH cells, right? How much battery current are you expecting to pull , pun intended... ?

2P sounds a little low, make sure you don't kill your investment prematurely.

 

[dimitri]

We have also discussed going with 33S 3P but that may drop the voltage too much to allow us to build enough momentum to keep the draw down for the last part of the pull.

Power is power, so 33S 3P will put the same stress on cells as 50S 2P , since decrease in voltge means proportional increase in current. The only way to address it is to add more cells, either 50S 3P or 33S 4P.

I have no hands on experience with stressing Headway cells to their limits, but I would check with someone who does. I think CroDriver has HeadWay pack in his BMW racer and he is likely giving it run for its money.

I would not just assume the cells can handle 20C just because the spreadsheet says so. Heat management and busbar connections become a concern when running at max C rates as well.