Reading the model code
B2A- Family segment. The 2A here is the balance-current class, not a pack rating: what governs JK-B2A24S20P is 2A active balancing, and the class comes with the family rather than being chosen separately.
24S- String ceiling, about 76.8V nominal on LiFePO4 cells. Take the cell count from the pack, not from the model name.
20P- Continuous discharge position. The spec table on this page lists 200A, and that is the figure to size cable, terminals and the protective device against.
What actually changes between these codes
Move across to JK-B2A24S15P and the only thing that changes inside B2A is continuous current — 200A here against 150A there, with the 24S ceiling and the 2A balance rate identical on both. US$53.00 separates the two at the base configuration. That makes it a load calculation rather than a feature decision.
JK-B2A20S20P holds the same 200A continuous rating and changes only the string ceiling: 4 fewer cells in series. Cell count is fixed by the pack being built, so it is the constraint that comes first.
JK-BD6A24S20P is the other candidate for the same pack: 24S, 200A, 0.6A balancing rather than 2A. It sits US$29.41 below this listing at the base configuration. If the cells are matched and the duty cycle leaves idle time, the cheaper of the two is the right answer; if they are not, no protection setting replaces balance current.
On price inside B2A this listing sits at 6 of 9: US$159.98 for the base configuration, against a family spread of US$89.98 (JK-B2A8S20P) to US$377.00 (JK-B2A25S-CR60P). Configuration add-ons shift that position, so compare like-for-like variants rather than headline figures.