> Are you saying there are some unstated engineering limitations that would hinder getting to the desired "C" by connecting more battery cells in parallel? Two

> Are you saying there are some unstated engineering limitations that would hinder getting to the desired "C" by connecting more battery cells in parallel? Two batteries in parallel have the same C rating! You double the output current, but you also double the capacity. When you put cells in series, you change the voltage but the current capability and capacity stay the same. In both cases the C rating doesn't change[1]. The C rating is just how quickly the battery can discharge itself, so it is entirely dependent on the chemistry and battery conditions. [1]: there are finer points; more batteries in series lowers output current slightly in practice, and batteries in parallel are quite complex to deal with. Cell size, construction and cooling all have large impacts on the C rating as well but at the end of the day it's simply how quickly a square centimeter of battery material can carry out its chemical reaction safely.