This PDF describes how to modify an Overkill Solar BMS for alternative cell counts.
Overkill Solar normally stocks 3 basic BMS models, which are configured for the most common Lithium Iron Phosphate (LiFePO4) battery setups: 4 cell 12v nominal, 8 cell 24v nominal, and 16 cell 48v nominal.
When using a different cell chemistry such as classic lithium ion, the number of cells needs to be adjusted to reach a usable system voltage. Common setups are 6 or 7 cells for a 24v system, and 12 or 13 cells for a 48v system.
Download the PDF instructions to read on: BMS_configuration_for_other_cell_counts-4S_and_8S-Overkill_Solar_LLC.pdf