One more thing, not battery related; I would suggest using a slightly higher resistance if you're wanting to use TC accurately with SS wire, particularly 316(L). The TCR of SS316 is low enough that it makes it easier for the board to monitor the temp change if the starting point is a little higher. Personally, I rarely go below 0.3 on SS temp control builds; many suggest 0.4, but the DNA is good enough to go a bit lower than that, IMO. For example, my Kayfun 5 is currently running at 0.35 and is working with TC like a champ.