Probably not as many as advertised (2000) since my charging method is not to specifications.
Also a BMS (battery managment system) probably would be required for cells in series.
Too bad a simple BMS couldn't be made from zener diodes and a mosfet somehow.
Maybe a zener diode could just be placed across the cell to limit charging voltage going too high.
But I think balancing the cells would be tricky since internal resistance could make all the cells in a battery discharge at different rates, eventually causing a cell to be reverse charged. It would require a microcontroller or human attention to keep the cells in a battery balanced. But one 3.2 volt cell at 100,000mAh could be used with a DC-DC boost converter..
https://overkillsolar.com/product/lifepo4-cell-100ah/Maybe.
The LiFePO4 cell is larger and heavier than a LI-ion cell.