Juiced says their 52V 19.2AH battery uses 84 cells, arranged in 14S-7P, which is 14 series groups with 7 cells in parallel within a group. The sum of the individual cell AH in a parallel group give the total Ah. For 19.2 AH and 7 cells, that means each cell is rated for 2.6AH, as 7 x 2.6AH is 19.2AH.
To get 20AH, they put in cells with higher AH capacity, Must be 3.0AH cells as 7 x 3.0AH is 21AH.