where 𝑑 is the maximum diameter of the jelly roll, 𝑑 is the diameter of the mandrel, and b is the height of the jelly roll. The volume of the jelly roll is equivalent to the volume of the stack of electrodes and separators, as shown in Figure . Looking at the sequence of the battery manufacturing process, it is seen that the final thickness is reached after calendering, whereas the length of the electrodes is reached only when they are trimmed by a semiautomatic winding machine to fit the maximum volume. So, once the final electrode thickness is calculated, the maximum electrode length that can fit in the casing can be found with the equation.